From owner-chemistry@ccl.net Sun Sep 10 08:12:00 2017 From: "Henrique C. S. Junior henriquecsj+/-gmail.com" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52981-170910080415-1079-8VrmebTgOpDvoyUwVQCynQ##server.ccl.net> X-Original-From: "Henrique C. S. Junior" Content-Type: multipart/alternative; boundary="94eb2c0ba0fc88a4800558d49be1" Date: Sun, 10 Sep 2017 09:03:28 -0300 MIME-Version: 1.0 Sent to CCL by: "Henrique C. S. Junior" [henriquecsj%%gmail.com] --94eb2c0ba0fc88a4800558d49be1 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose molecul= ar structure was achieved by Single Crystal X-Ray Diffraction. My task now is to check the spin states of the structure (High or Low spin). Since Co(II) can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem by calculating Single Points for every possible multiplicity (10, 8, 6, 4, 2) and assuming that the most stable is the one that represents my structure (and my spin states). Is this approach correct? Thank you --=20 *Henrique C. S. Junior* --94eb2c0ba0fc88a4800558d49be1 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

Dear colleagues, I=E2=80=99m working= with a Cobalt(II) trimer whose molecular structure was achieved by Single = Crystal X-Ray Diffraction. My task now is to check the spin states of the s= tructure (High or Low spin). Since Co(II) can have 1 or 3 unpaired electron= s, I=E2=80=99m approaching this problem by calculating Single Points for ev= ery possible multiplicity (10, 8, 6, 4, 2) and assuming that the most stabl= e is the one that represents my structure (and my spin states).

Is this approach correct?

Thank you


--
Henrique C. S. Junior

--94eb2c0ba0fc88a4800558d49be1-- From owner-chemistry@ccl.net Sun Sep 10 10:10:01 2017 From: "Sergio Emanuel Galembeck segalemb]-[usp.br" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52982-170910100734-6239-hTitDK8LdE2528rtmp+xtg!A!server.ccl.net> X-Original-From: Sergio Emanuel Galembeck Content-Type: multipart/alternative; boundary="001a114257acd3596a0558d653be" Date: Sun, 10 Sep 2017 11:07:15 -0300 MIME-Version: 1.0 Sent to CCL by: Sergio Emanuel Galembeck [segalemb]-[usp.br] --001a114257acd3596a0558d653be Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Henrique, I suggest that for each spin state you optimize the geometry. Some of this states could generate an unstable geometry. Best regards, Sergio Prof. Sergio Emanuel Galembeck Computational Quantum Chemistry Laboratory Departamento de Qu=C3=ADmica - FFCLRP-USP Av. Bandeirantes, 3900 14040-901 - Ribeirao Preto-SP Brasil phone: +55(16)33153765 segalemb() usp.br 2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior henriquecsj+/-gmail.com < owner-chemistry() ccl.net>: > Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose molec= ular > structure was achieved by Single Crystal X-Ray Diffraction. My task now i= s > to check the spin states of the structure (High or Low spin). Since Co(II= ) > can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem = by > calculating Single Points for every possible multiplicity (10, 8, 6, 4, 2= ) > and assuming that the most stable is the one that represents my structure > (and my spin states). > > Is this approach correct? > > Thank you > > -- > *Henrique C. S. Junior* > > --001a114257acd3596a0558d653be Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear Henrique,

I suggest that for each = spin state you optimize the geometry. Some of this states could generate an= unstable geometry.=C2=A0

Best regards,
=
Sergio

<= div dir=3D"ltr">
Prof. Sergio Emanuel Galembeck
<= div dir=3D"ltr">Computational Quantum Chemistry Laboratory
Departam= ento de Qu=C3=ADmica - FFCLRP-USP
Av. Bandeirantes, 3900
14040-901 - Ribeirao Preto-SP
Brasil

p= hone: +55(16)33153765

2017-09-10 9:03 GMT-03:00 Henrique C. S. Jun= ior henriquecsj+/-gmail.com <owner-= chemistry() ccl.net>:

Dear colleagues, I=E2=80=99m working with a= Cobalt(II) trimer whose molecular structure was achieved by Single Crystal= X-Ray Diffraction. My task now is to check the spin states of the structur= e (High or Low spin). Since Co(II) can have 1 or 3 unpaired electrons, I=E2= =80=99m approaching this problem by calculating Single Points for every pos= sible multiplicity (10, 8, 6, 4, 2) and assuming that the most stable is th= e one that represents my structure (and my spin states).

Is this approach correct?

Thank you


--
<= span style=3D"color:rgb(139,139,139)"><= b>Henrique C. S. Junior


--001a114257acd3596a0558d653be-- From owner-chemistry@ccl.net Sun Sep 10 10:45:00 2017 From: "Tandon Swetanshu tandons.++.tcd.ie" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52983-170910104322-21501-Dt4223HCrVurql28snQ73A++server.ccl.net> X-Original-From: Tandon Swetanshu Content-Type: multipart/alternative; boundary="f403045f40969b1dba0558d6d488" Date: Sun, 10 Sep 2017 15:43:16 +0100 MIME-Version: 1.0 Sent to CCL by: Tandon Swetanshu [tandons() tcd.ie] --f403045f40969b1dba0558d6d488 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Henrique, For your single point calculations, make sure that you confirm that the wavefunction does not have any instabilities (especially in the case of low spins). Additionally you need to know the temperature at which the X-ray measurement was performed. This is because, the differences in the energies of different spin states is generally quite small. So there is a possibility that, at the temperature at which X-ray measurement was performed, a number of spin states co-exist and the X-ray strucutre, thus, might be a mixture of spin states. Hope that helps. Good luck, Swetanshu. On 10 September 2017 at 13:03, Henrique C. S. Junior henriquecsj+/-gmail.co= m wrote: > Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose molec= ular > structure was achieved by Single Crystal X-Ray Diffraction. My task now i= s > to check the spin states of the structure (High or Low spin). Since Co(II= ) > can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem = by > calculating Single Points for every possible multiplicity (10, 8, 6, 4, 2= ) > and assuming that the most stable is the one that represents my structure > (and my spin states). > > Is this approach correct? > > Thank you > > -- > *Henrique C. S. Junior* > > --f403045f40969b1dba0558d6d488 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Henrique,

For you= r single point calculations, make sure that you confirm that the wavefuncti= on does not have any instabilities (especially in the case of low spins).

Additionally you need to know the temperature at whi= ch the X-ray measurement was performed. This is because, the differences in= the energies of different spin states is generally quite small. So there i= s a possibility that, at the temperature at which X-ray measurement was per= formed, a number of spin states co-exist and the X-ray strucutre, thus, mig= ht be a mixture of spin states.

Hope that helps.

= Good luck,
Swetanshu.

On 10 September 2017 at 13:03, Henrique C. S. Junior= henriquecsj+/-gmail.com <owner-che= mistry{=}ccl.net> wrote:

Dear colleagues, I=E2=80=99m working wit= h a Cobalt(II) trimer whose molecular structure was achieved by Single Crys= tal X-Ray Diffraction. My task now is to check the spin states of the struc= ture (High or Low spin). Since Co(II) can have 1 or 3 unpaired electrons, I= =E2=80=99m approaching this problem by calculating Single Points for every = possible multiplicity (10, 8, 6, 4, 2) and assuming that the most stable is= the one that represents my structure (and my spin states).

Is this approach correct?

Thank you


--
Henrique C. S. Junior


--f403045f40969b1dba0558d6d488-- From owner-chemistry@ccl.net Sun Sep 10 11:20:01 2017 From: "Marcel Swart marcel.swart-$-icrea.cat" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52984-170910110547-2330-qfUGCOLI1iHSLV2QOPitVw- -server.ccl.net> X-Original-From: Marcel Swart Content-Type: multipart/alternative; boundary="Apple-Mail=_4F219353-F975-48CA-8BF2-64658CA1C547" Date: Sun, 10 Sep 2017 17:05:38 +0200 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Sent to CCL by: Marcel Swart [marcel.swart*_*icrea.cat] --Apple-Mail=_4F219353-F975-48CA-8BF2-64658CA1C547 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Dear Henrique, Furthermore it can be anti-ferromagnetically coupled. Probably the best initial check is look at the Co-ligand distances, and compare these with known mono-nuclear Co-complexes, to see what the most likely spin state is. Note: before even doing one calculation, reset the hydrogen distances, either manually or with some GUI program; X-ray gives wrong distances for them, with O-H of 0.85, N-H of 0.91 and C-H of 0.95 Angs. These are all ca. 0.10-0.15 =C3=85 too short, and will lead to SCF = problems. Marcel > On 10 Sep 2017, at 14:03, Henrique C. S. Junior = henriquecsj+/-gmail.com wrote: >=20 > Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose = molecular structure was achieved by Single Crystal X-Ray Diffraction. My = task now is to check the spin states of the structure (High or Low = spin). Since Co(II) can have 1 or 3 unpaired electrons, I=E2=80=99m = approaching this problem by calculating Single Points for every possible = multiplicity (10, 8, 6, 4, 2) and assuming that the most stable is the = one that represents my structure (and my spin states). >=20 > Is this approach correct? >=20 > Thank you >=20 >=20 > --=20 > Henrique C. S. Junior >=20 _____________________________________ Prof. Dr. Marcel Swart, FRSC FYAE ICREA Research Professor at Institut de Qu=C3=ADmica Computacional i Cat=C3=A0lisi (IQCC) Univ. Girona (Spain) Chair Young Academy of Europe Director IQCC Chair COST Action CM1305 (ECOSTBio) Organizer Girona Seminar 2018 web http://www.marcelswart.eu vCard addressbook://www.marcelswart.eu/MSwart.vcf --Apple-Mail=_4F219353-F975-48CA-8BF2-64658CA1C547 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Dear Henrique,

Furthermore it can be anti-ferromagnetically = coupled.
Probably the best initial check is look at = the Co-ligand distances,
and compare these with = known mono-nuclear Co-complexes,
to see what the = most likely spin state is.

Note:
before even doing one calculation, = reset the hydrogen distances,
either manually or = with some GUI program; X-ray gives wrong
distances = for them, with O-H of 0.85, N-H of 0.91 and C-H of 0.95 Angs.
These are all ca. 0.10-0.15 =C3=85 too short, and will lead = to SCF problems.

Marcel

On 10 Sep 2017, at 14:03, = Henrique C. S. Junior henriquecsj+/-gmail.com <owner-chemistry() ccl.net> wrote:

Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer = whose molecular structure was achieved by Single Crystal X-Ray = Diffraction. My task now is to check the spin states of the structure = (High or Low spin). Since Co(II) can have 1 or 3 unpaired electrons, = I=E2=80=99m approaching this problem by calculating Single Points for = every possible multiplicity (10, 8, 6, 4, 2) and assuming that the most = stable is the one that represents my structure (and my spin = states).

Is this approach = correct?

Thank you


--
Henrique C. S. Junior

<= /div>


_____________________________________
Prof. Dr. Marcel Swart, FRSC FYAE

ICREA Research Professor at
Institut de = Qu=C3=ADmica Computacional i Cat=C3=A0lisi (IQCC)
Univ. = Girona (Spain)

Chair Young Academy of Europe
Director IQCC
Chair COST Action = CM1305 (ECOSTBio)
Organizer Girona Seminar 2018

web
http://www.marcelswart.eu
vCard
addressbook://www.marcelswart.eu/MSwart.vcf






= --Apple-Mail=_4F219353-F975-48CA-8BF2-64658CA1C547-- From owner-chemistry@ccl.net Sun Sep 10 11:54:00 2017 From: "Elvis Martis elvis_bcp.,,.elvismartis.in" To: CCL Subject: CCL:G: AM1-BCC charges in Antechamber Message-Id: <-52985-170909215719-25876-XV5wdXsDCkIDZ8cul3EJaQ,,server.ccl.net> X-Original-From: Elvis Martis Content-Type: multipart/alternative; boundary="001a113fb8f8e2122b0558cc20be" Date: Sun, 10 Sep 2017 07:27:10 +0530 MIME-Version: 1.0 Sent to CCL by: Elvis Martis [elvis_bcp+/-elvismartis.in] --001a113fb8f8e2122b0558cc20be Content-Type: text/plain; charset="UTF-8" Hi Zach, You should post this on the Amber Mailing List as well. Have you tried optimizing this molecule using gaussian? Trying optimizing the geometry in gaussian first at any level of theory. Then derive the ESPs on this optimized geometry. Then you can use antechamber to fit the charges using resp. Hope this helps. On Sunday, September 10, 2017, Zachary B Smithline zachary.smithline(0) yale.edu wrote: > > Sent to CCL by: "Zachary B Smithline" [zachary.smithline]_[yale.edu] > Dear All, > > Does anybody have a lot of experience deriving AM1-BCC charges quickly in > Antechamber? I am > trying to parameterize charges for: 3' adenine nucleotide with its 3'O > deprotonated (since the 3' > terminal residues in Amber usually have -0.6921 charge, my residue should > have -1.6921); > pyrophosphate (charge -4); and dATP (charge -4). > > After generating .pdbs, I was trying to run the command: > > antechamber -i FILE_NAME.pdb -fi pdb -o FILE_NAME.mol2 -fo mol2 -c bcc -s > 2 -nc CHARGE > > Both dATP and pyrophosphate give me errors when I use -nc -4; however, > when I decrease the > charge (say, to -2), the antechamber command works. Is it ok to assume the > charge distributes > uniformly as it is decreased, meaning: can I just double all my charges? > > For the 3' adenine nucleotide with its 3'O deprotonated, I don't think > antechamber will take a > non-integer charge. Can I use the same strategy, and just scale the > charges? If not, does > anybody have a suggestion as to how to deal with these problems? Is there > any simple way to do > these tasks in Antechamber? > > Many thanks, > Zach Smithline > Lab of Thomas Steitz > Departments of MB&B and Chemistry > Yale University> > E-mail to subscribers: CHEMISTRY%ccl.net or use:> > E-mail to administrators: CHEMISTRY-REQUEST%ccl.net or use> > > -- Greetings Elvis Martis BCP, Mumbai. --001a113fb8f8e2122b0558cc20be Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Zach,
You should post this on the Amber Mailing
List as we= ll.=C2=A0
Have you tried optimizing this molecule using gaussian?= =C2=A0
Trying optimizing the geometry in gaussian first at any le= vel of theory. Then=C2=A0derive the ESPs=C2=A0on this optimized geometry. T= hen you can use antechamber to fit the charges using resp.=C2=A0
= Hope this helps.=C2=A0

On Sunday, September 10, 2017, Zachary B Smit= hline zachary.smithline(0)yale.edu <owner-chemistry%ccl.net> wrot= e:

Sent to CCL by: "Zachary B Smithline" [zachary.smithline]_[yale.edu]
Dear All,

Does anybody have a lot of experience deriving AM1-BCC charges quickly in A= ntechamber?=C2=A0 I am
trying to parameterize charges for: 3' adenine nucleotide with its 3= 9;O deprotonated (since the 3'
terminal residues in Amber usually have -0.6921 charge, my residue should h= ave -1.6921);
pyrophosphate (charge -4); and dATP (charge -4).

After generating .pdbs, I was trying to run the command:

antechamber -i FILE_NAME.pdb -fi pdb -o FILE_NAME.mol2 -fo mol2 -c bcc -s 2= -nc CHARGE

Both dATP and pyrophosphate give me errors when I use -nc -4; however, when= I decrease the
charge (say, to -2), the antechamber command works. Is it ok to assume the = charge distributes
uniformly as it is decreased, meaning: can I just double all my charges?
For the 3' adenine nucleotide with its 3'O deprotonated, I don'= t think antechamber will take a
non-integer charge. Can I use the same strategy, and just scale the charges= ?=C2=A0 If not, does
anybody have a suggestion as to how to deal with these problems? Is there a= ny simple way to do
these tasks in Antechamber?

Many thanks,
Zach Smithline
Lab of Thomas Steitz
Departments of MB&B and Chemistry
Yale University



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--
Greetings
Elvis Martis
BCP, Mumbai.=
--001a113fb8f8e2122b0558cc20be-- From owner-chemistry@ccl.net Sun Sep 10 12:29:01 2017 From: "Andreas Klamt klamt_-_cosmologic.de" To: CCL Subject: CCL:G: Gaussian SCRF error "No solvent atoms in DisRep" Message-Id: <-52986-170910072532-31128-3BI+lNDPxtDtbwFlZu7yxQ!=!server.ccl.net> X-Original-From: Andreas Klamt Content-Type: multipart/alternative; boundary="------------BB306B72B716D4E378BB15E1" Date: Sun, 10 Sep 2017 13:25:09 +0200 MIME-Version: 1.0 Sent to CCL by: Andreas Klamt [klamt : cosmologic.de] This is a multi-part message in MIME format. --------------BB306B72B716D4E378BB15E1 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Dear Igors, Gaussian surely is not so happy if they claimed advantage of IEFPCM over COSMO is not real. Can you tell me how big the molecule with escaped charge of 0.46 e is? This either means, that too small radii have been used somewhere, or that the molecule is very big, so that even with COSMO (C-PCM) the error is that large. By the way, this error does not depend on epsilon. And what does the "Error on total polarization charges = 0.30616 "mean? It is claimed to be only 0.01 for IEFPCM. Andreas Am 09.09.2017 um 21:24 schrieb Igors Mihailovs igorsm###cfi.lu.lv: > Dear Dr. Zou, > > Thank You for the further clarification! > > One another thing I am a little curious about -- only in CPCM+SMD > calculation the escaped charge is /reported/ (in my case, enormous > 0.46984). Is that because of some threshold for things to appear in > output, or due to a different algorithm in use (for IEFPCM, even with > #P there is no sign of escaped charge)? > > Dear Dr. Klamt, > > That's why I was surprised by the results I had got, because I have > read before, well, at least the abstract of the article You cited (due > to the lack of access) /and/ Your article of 2011 (DOI: > 10.1002/wcms.56 ) where You argued > that, although it was proven that the best value of /x/ in the > equation for COSMO is 0.5, "[u]nfortunately, several reimplementations > of COSMO, including C-PCM, set the value of /x/ to zero either by > default or fixed." Can this be the reason? Or is it simply because SMD > model in Gaussian is optimized for IEFPCM, not CPCM?(Maybe Dr. Zou can > comment on that.) > You also mention that "in the literature the COSMO approximation is > often claimed to be applicable only to polar solvents, it needs to be > emphasized that for neutral compounds the COSMO approximation with x = > 0.5 provides very accurate results down to ε = 2". Maybe this is why > COSMO is not that popular? On the other hand, if, as Dr. Zou said, the > differences in computational cost arise only in really large > molecules, maybe software developers just feel it is not that urgent > to implement COSMO if they already have another methods implemented… > > By "the equation" I mean the equation of COSMO scaling factor for > unscreened charge density, > > /f/ (/ε/) = (/ε/ – 1) / (/ε/ + /x/) > > --------------------------------------------------------------------------- > > To mention some other details, the differing part in the output is the > following: > > ***** CPCM_SMD.out > No special actions if energy rises. > Using charges instead of weights in PCMQM. > Inv3: Mode=1 IEnd= 5838075. > Iteration 1 A*A^-1 deviation from unit magnitude is 2.78D-15 > for 865. > Iteration 1 A*A^-1 deviation from orthogonality is 1.65D-15 > for 711 187. > Iteration 1 A^-1*A deviation from unit magnitude is 3.11D-15 > for 813. > Iteration 1 A^-1*A deviation from orthogonality is 1.65D-15 for > 1142 64. > Escaped charge = 0.46984 > Error on total polarization charges = 0.30616 > SCF Done: E(RB3LYP) = -492.141763479 A.U. after 13 cycles > NFock= 13 Conv=0.34D-08 -V/T= 2.0086 > SMD-CDS (non-electrostatic) energy (kcal/mol) = -1.55 > > ***** IEFPCM_SMD.OUT > No special actions if energy rises. > Inv3: Mode=1 IEnd= 5838075. > Iteration 1 A*A^-1 deviation from unit magnitude is 3.55D-15 > for 317. > Iteration 1 A*A^-1 deviation from orthogonality is 2.67D-15 > for 629 474. > Iteration 1 A^-1*A deviation from unit magnitude is 3.33D-15 > for 317. > Iteration 1 A^-1*A deviation from orthogonality is 2.19D-15 > for 545 224. > Error on total polarization charges = 0.01601 > SCF Done: E(RB3LYP) = -492.138961313 A.U. after 13 cycles > NFock= 13 Conv=0.35D-08 -V/T= 2.0086 > SMD-CDS (non-electrostatic) energy (kcal/mol) = -1.55 > > > Yours sincerely, > Igors Mihailovs > ISSP UL > > On 08/09/17 22:59, Lufeng Zou g09gv5_+_gmail.com wrote: >> Hello Igors, >> >> One thing to add is that SMD is a solvation model (IEFPCM using SMD >> radii for electrostatic part, plus nonelectrostatic terms), so please >> do not combine SMD with other solvation models. The program should >> have recognized this error and abort, thank you for catching the bug. >> >> As for the cost, please rest assured that difference between IEFPCM >> and CPCM will be minor for most calculations. The only exception is >> that for very large molecules with hundreds of atoms, more MEMORY >> (RAM) is required for IEFPCM than CPCM. >> >> Lufeng Zou, Ph.D. >> Technical Support >> Gaussian, Inc. >> help . gaussian.com > > > On 09/09/17 04:16, Andreas Klamt klamt#cosmologic.de wrote: >> For the differences of IEFPCM and CPCM see >> Comprehensive Comparison of the IEFPCM and SS(V)PE Continuum >> Solvation Methods with the COSMO Approach >> http://pubs.acs.org/doi/abs/10.1021/acs.jctc.5b00601?src=recsys&journalCode=jctcce >> >> They are indeed essentially identical. Hence I do not really >> understand why the more complicated IEFPCM is so much in use. >> >> Andreas -- -------------------------------------------------- Prof. Dr. Andreas Klamt CEO / Geschäftsführer COSMOlogic GmbH & Co. KG Imbacher Weg 46 D-51379 Leverkusen, Germany phone +49-2171-731681 fax +49-2171-731689 e-mail klamt(~)cosmologic.de web www.cosmologic.de [University address: Inst. of Physical and Theoretical Chemistry, University of Regensburg] HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt Komplementaer: COSMOlogic Verwaltungs GmbH HRB 49501 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt --------------BB306B72B716D4E378BB15E1 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit
Dear Igors,

Gaussian surely is not so happy if they claimed advantage of IEFPCM over COSMO is not real.

Can you tell me how big the molecule with escaped charge of  0.46 e is?
This either means, that too small radii have been used somewhere, or that the molecule is very big, so that even with COSMO (C-PCM) the error is that large. By the way, this error does not depend on epsilon.

And what does the
"Error on total polarization charges =  0.30616 "mean?
It is claimed to be only 0.01 for IEFPCM.

Andreas


Am 09.09.2017 um 21:24 schrieb Igors Mihailovs igorsm###cfi.lu.lv:
Dear Dr. Zou,

Thank You for the further clarification!

One another thing I am a little curious about -- only in CPCM+SMD calculation the escaped charge is reported (in my case, enormous 0.46984). Is that because of some threshold for things to appear in output, or due to a different algorithm in use (for IEFPCM, even with #P there is no sign of escaped charge)?

Dear Dr. Klamt,

That's why I was surprised by the results I had got, because I have read before, well, at least the abstract of the article You cited (due to the lack of access) and Your article of 2011 (DOI: 10.1002/wcms.56) where You argued that, although it was proven that the best value of x in the equation for COSMO is 0.5, "[u]nfortunately, several reimplementations of COSMO, including C-PCM, set the value of x to zero either by default or fixed." Can this be the reason? Or is it simply because SMD model in Gaussian is optimized for IEFPCM, not CPCM? (Maybe Dr. Zou can comment on that.)
You also mention that "in the literature the COSMO approximation is often claimed to be applicable only to polar solvents, it needs to be emphasized that for neutral compounds the COSMO approximation with x = 0.5 provides very accurate results down to ε = 2". Maybe this is why COSMO is not that popular? On the other hand, if, as Dr. Zou said, the differences in computational cost arise only in really large molecules, maybe software developers just feel it is not that urgent to implement COSMO if they already have another methods implemented…

By "the equation" I mean the equation of COSMO scaling factor for unscreened charge density,

f (ε) = (ε – 1) / (ε + x)

---------------------------------------------------------------------------

To mention some other details, the differing part in the output is the following:

***** CPCM_SMD.out
 No special actions if energy rises.
 Using charges instead of weights in PCMQM.
 Inv3:  Mode=1 IEnd=     5838075.
 Iteration    1 A*A^-1 deviation from unit magnitude is 2.78D-15 for    865.
 Iteration    1 A*A^-1 deviation from orthogonality  is 1.65D-15 for    711    187.
 Iteration    1 A^-1*A deviation from unit magnitude is 3.11D-15 for    813.
 Iteration    1 A^-1*A deviation from orthogonality  is 1.65D-15 for   1142     64.
 Escaped charge =  0.46984
 Error on total polarization charges =  0.30616
 SCF Done:  E(RB3LYP) =  -492.141763479     A.U. after   13 cycles
            NFock= 13  Conv=0.34D-08     -V/T= 2.0086
 SMD-CDS (non-electrostatic) energy       (kcal/mol) =      -1.55

***** IEFPCM_SMD.OUT
 No special actions if energy rises.
 Inv3:  Mode=1 IEnd=     5838075.
 Iteration    1 A*A^-1 deviation from unit magnitude is 3.55D-15 for    317.
 Iteration    1 A*A^-1 deviation from orthogonality  is 2.67D-15 for    629    474.
 Iteration    1 A^-1*A deviation from unit magnitude is 3.33D-15 for    317.
 Iteration    1 A^-1*A deviation from orthogonality  is 2.19D-15 for    545    224.
 Error on total polarization charges =  0.01601
 SCF Done:  E(RB3LYP) =  -492.138961313     A.U. after   13 cycles
            NFock= 13  Conv=0.35D-08     -V/T= 2.0086
 SMD-CDS (non-electrostatic) energy       (kcal/mol) =      -1.55


Yours sincerely,
Igors Mihailovs
ISSP UL

On 08/09/17 22:59, Lufeng Zou g09gv5_+_gmail.com wrote:
Hello Igors,

One thing to add is that SMD is a solvation model (IEFPCM using SMD radii for electrostatic part, plus nonelectrostatic terms), so please do not combine SMD with other solvation models. The program should have recognized this error and abort, thank you for catching the bug.

As for the cost, please rest assured that difference between IEFPCM and CPCM will be minor for most calculations. The only exception is that for very large molecules with hundreds of atoms, more MEMORY (RAM) is required for IEFPCM than CPCM.

Lufeng Zou, Ph.D.
Technical Support
Gaussian, Inc.
help . gaussian.com


On 09/09/17 04:16, Andreas Klamt klamt#cosmologic.de wrote:
For the differences of IEFPCM and CPCM see
 Comprehensive Comparison of the IEFPCM and SS(V)PE Continuum Solvation Methods with the COSMO Approach
http://pubs.acs.org/doi/abs/10.1021/acs.jctc.5b00601?src=recsys&journalCode=jctcce

They are indeed essentially identical. Hence I do not really understand why the more complicated IEFPCM is so much in use.

Andreas


-- 
--------------------------------------------------

Prof. Dr. Andreas Klamt
CEO / Geschäftsführer
COSMOlogic GmbH & Co. KG
Imbacher Weg 46
D-51379 Leverkusen, Germany

phone  	+49-2171-731681
fax    	+49-2171-731689
e-mail 	klamt(~)cosmologic.de
web    	www.cosmologic.de

[University address:      Inst. of Physical and
Theoretical Chemistry, University of Regensburg]

HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt
Komplementaer: COSMOlogic Verwaltungs GmbH
HRB 49501 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt
--------------BB306B72B716D4E378BB15E1-- From owner-chemistry@ccl.net Sun Sep 10 13:04:01 2017 From: "Andrew Rosen rosen###u.northwestern.edu" To: CCL Subject: CCL:G: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52987-170910105138-25902-3WNKmYOHHpO7UTvEG6kqmg]-[server.ccl.net> X-Original-From: Andrew Rosen Content-Type: multipart/alternative; boundary="001a1138e216fe82c30558d6f197" Date: Sun, 10 Sep 2017 14:51:19 +0000 MIME-Version: 1.0 Sent to CCL by: Andrew Rosen [rosen|u.northwestern.edu] --001a1138e216fe82c30558d6f197 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Henrique, I am going to preface this by saying that this is a deceivingly challenging task. I am a young graduate student who is very much still learning, so if others reading this disagree with something I say, please feel free to chime in. In general, you have the right idea, although there are a few things to consider. My response is in the context of DFT, which I imagine is what you're using. 1. I assume you are using the structure from XRD in your electronic structure calculations. It is likely that at the level of theory you choose, the XRD structure is not exactly the minimum energy structure (although it is hopefully quite close!). In that case, it may be advisable to do a geometry optimization from this experimental geometry instead of a single point energy calculation at each spin multiplicity. This may also be beneficial, albeit more computationally tasking, because different spin states can lead to different molecular geometries. Oftentimes, this difference may be small, but it has the possibility of impacting the energetics. The chapter on "Spin interactions in cluster chemistry" in the text "Advances in Inorganic Chemistry Volume 62: Theoretical and Computational Inorganic Chemistry" may be quite useful. A publicly accessible link to the relevant section on Google Books is found here . Pages 216-222 are extremely relevant to this discussion. 2. You should check to see the degree of spin contamination in your calculations, as discussed here . If it is large, it could signify that the level of theory you chose is not sufficient for the problem at hand and the energetics as well as other molecular properties may not be accurate. In such cases, it may be necessary to consider more accurate multireference methods. 3. It can often be difficult to accurately capture the relative energies of various spin states for transition metal complexes using DFT, and this can often be very sensitive to the choice of density functional. As discussed here , pure functionals tend to favor low-spin states whereas hybrid functions tend to favor high-spin states, and the energy difference between low- and high-spin states is often directly related to the amount of Hartree-Fock exchange in a given functional. This is a limitation to keep in mind. 4. There is the possibility that a broken-symmetry state is most stable. While this is likely a bit more involved than what you are looking to check for (especially given this is a trimer), it is worth realizing that such a possibility exists, as discussed here in the context of Gaussian or here in the context of ORCA. 5. At times, it may be necessary to check the stability of the wavefunction when dealing with open-shell structures. A detailed discussion on StackExchange can be found here . In the end, yes, you are correct that you must do this "manually" and compare the energetics of different possible spin multiplicities. Your approach may end up being sufficient, but as I mentioned, there are some factors that you should at the very least keep in mind. Andrew On Sun, Sep 10, 2017 at 8:20 AM Henrique C. S. Junior henriquecsj+/- gmail.com wrote: > Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose molec= ular > structure was achieved by Single Crystal X-Ray Diffraction. My task now i= s > to check the spin states of the structure (High or Low spin). Since Co(II= ) > can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem = by > calculating Single Points for every possible multiplicity (10, 8, 6, 4, 2= ) > and assuming that the most stable is the one that represents my structure > (and my spin states). > > Is this approach correct? > > Thank you > > -- > *Henrique C. S. Junior* > > --001a1138e216fe82c30558d6f197 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Henrique,

I am going to= preface this by saying that this is a deceivingly challenging task. I am a= young graduate student who is very much still learning, so if others readi= ng this disagree with something I say, please feel free to chime in. In gen= eral, you have the right idea, although there are a few things to consider.= My response is in the context of DFT, which I imagine is what you're u= sing.

1. I assume you are using the structure from XRD in your electronic= structure calculations. It is likely that at the level of theory you choos= e, the XRD structure is not exactly the minimum energy structure (although = it is hopefully quite close!). In that case, it may be advisable to do a ge= ometry optimization from this experimental geometry instead of a single poi= nt energy calculation at each spin multiplicity. This may also be beneficia= l, albeit more computationally tasking, because different spin states can l= ead to different molecular geometries. Oftentimes, this difference may be s= mall, but it has the possibility of impacting the energetics. The chapter o= n "Spin interactions in cluster chemistry" in the text "Adva= nces in Inorganic Chemistry Volume 62: Theoretical and Computational Inorga= nic Chemistry" may be quite useful. A publicly accessible link to the = relevant section on Google Books is found=C2=A0here. Pages 216-222 are extrem= ely relevant to this discussion.

2. You should check to see the degree of= spin contamination in your calculations, as discussed=C2=A0here. I= f it is large, it could signify that the level of theory you chose is not s= ufficient for the problem at hand and the energetics as well as other molec= ular properties may not be accurate. In such cases, it may be necessary to = consider more accurate multireference methods.

3. It can often be difficu= lt to accurately capture the relative energies of various spin states for t= ransition metal complexes using DFT, and this can often be very sensitive t= o the choice of density functional. As discussed=C2=A0here, pure functionals tend= to favor low-spin states whereas hybrid functions tend to favor high-spin = states, and the energy difference between low- and high-spin states is ofte= n directly related to the amount of Hartree-Fock exchange in a given functi= onal. This is a limitation to keep in mind.

4. There is the possibility t= hat a broken-symmetry state is most stable. While this is likely a bit more= involved than what you are looking to check for (especially given this is = a trimer), it is worth realizing that such a possibility exists, as discuss= ed=C2=A0here=C2=A0in the context o= f Gaussian or=C2=A0here=C2=A0in the context of ORCA.

5. At ti= mes, it may be necessary to check the stability of the wavefunction when de= aling with open-shell structures. A detailed discussion on StackExchange ca= n be found=C2=A0here.

In the end, yes, you are correct that you must do th= is "manually" and compare the energetics of different possible sp= in multiplicities. Your approach may end up being sufficient, but as I ment= ioned, there are some factors that you should at the very least keep in min= d.

Andrew

On S= un, Sep 10, 2017 at 8:20 AM Henrique C. S. Junior henriquecsj+/-gmail.com <owner-chemistry.:.ccl.net> wrote:

Dear colleagues, I=E2=80=99m= working with a Cobalt(II) trimer whose molecular structure was achieved by= Single Crystal X-Ray Diffraction. My task now is to check the spin states = of the structure (High or Low spin). Since Co(II) can have 1 or 3 unpaired = electrons, I=E2=80=99m approaching this problem by calculating Single Point= s for every possible multiplicity (10, 8, 6, 4, 2) and assuming that the mo= st stable is the one that represents my structure (and my spin states).

Is this approach correct?

Thank you


--
Henrique C. S. Junior

--001a1138e216fe82c30558d6f197-- From owner-chemistry@ccl.net Sun Sep 10 13:39:01 2017 From: "Henrique C. S. Junior henriquecsj,+,gmail.com" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52988-170910122154-32766-U/Mob69gdrvbolzzLoZ3vQ-x-server.ccl.net> X-Original-From: "Henrique C. S. Junior" Content-Type: multipart/alternative; boundary="94eb2c117190ff5bbd0558d8347c" Date: Sun, 10 Sep 2017 13:21:08 -0300 MIME-Version: 1.0 Sent to CCL by: "Henrique C. S. Junior" [henriquecsj++gmail.com] --94eb2c117190ff5bbd0558d8347c Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Sergio, thanks for your reply. I forgot to tell that this structure is to be used to study magnetic couplings, so we usually don't perform geometry optimizations. Despite that, do you believe that the Single Points approach is, in general, correct? On Sun, Sep 10, 2017 at 11:07 AM, Sergio Emanuel Galembeck segalemb]-[usp.b= r wrote: > Dear Henrique, > > I suggest that for each spin state you optimize the geometry. Some of thi= s > states could generate an unstable geometry. > > Best regards, > > Sergio > > Prof. Sergio Emanuel Galembeck > Computational Quantum Chemistry Laboratory > Departamento de Qu=C3=ADmica - FFCLRP-USP > Av. Bandeirantes, 3900 > > 14040-901 - Ribeirao Preto-SP > Brasil > > phone: +55(16)33153765 <(16)%203315-3765> > segalemb~!~usp.br > > 2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior henriquecsj+/-gmail.com < > owner-chemistry~!~ccl.net>: > >> Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose mole= cular >> structure was achieved by Single Crystal X-Ray Diffraction. My task now = is >> to check the spin states of the structure (High or Low spin). Since Co(I= I) >> can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem= by >> calculating Single Points for every possible multiplicity (10, 8, 6, 4, = 2) >> and assuming that the most stable is the one that represents my structur= e >> (and my spin states). >> >> Is this approach correct? >> >> Thank you >> >> -- >> *Henrique C. S. Junior* >> >> > --=20 *Henrique C. S. Junior* Industrial Chemist - UFRRJ M. Sc. Inorganic Chemistry - UFRRJ Data Processing Center - PMP Visite o Mundo Qu=C3=ADmico --94eb2c117190ff5bbd0558d8347c Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear Sergio, thanks for your reply. I forgot to tell that this= structure is to be used to study magnetic couplings, so we usually don'= ;t perform geometry optimizations.
Despite that, do you believe that the = Single Points approach is, in general, correct?

On Sun, Sep 10, 2017 at 11:07 AM,= Sergio Emanuel Galembeck segalemb]-[usp.br <= span dir=3D"ltr"><owner-chemistry() ccl.net> wrote:
Dear Henrique,

I suggest = that for each spin state you optimize the geometry. Some of this states cou= ld generate an unstable geometry.=C2=A0

Best regar= ds,

Sergio
<= br clear=3D"all">
Prof= . Sergio Emanuel Galembeck
Computational Quantum Chem= istry Laboratory
Departamento de Qu=C3=ADmica - FFCLRP-USP
Av. Bandeirantes, 3900
14040-901 - R= ibeirao Preto-SP
Brasil


2017-09-10 9:03 GMT-03:00 Henrique C. S. Jun= ior henriquecsj+/-gmail.com<= /a> <owner-chemistry~!~ccl.net>:

Dear colleagues, I=E2= =80=99m working with a Cobalt(II) trimer whose molecular structure was achi= eved by Single Crystal X-Ray Diffraction. My task now is to check the spin = states of the structure (High or Low spin). Since Co(II) can have 1 or 3 un= paired electrons, I=E2=80=99m approaching this problem by calculating Singl= e Points for every possible multiplicity (10, 8, 6, 4, 2) and assuming that= the most stable is the one that represents my structure (and my spin state= s).

Is this approach correct?

Thank you


--
= Henrique C. = S. Junior





--
Henrique C. S. Junior
Industrial= Chemist - UFRRJ
M. Sc. Inorganic Chemi= stry - UFRRJ
Data Processing Center - PMP
<= div>Visite o Mundo= Qu=C3=ADmico
--94eb2c117190ff5bbd0558d8347c-- From owner-chemistry@ccl.net Sun Sep 10 14:14:01 2017 From: "Neese, Frank frank.neese * cec.mpg.de" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52989-170910124408-22379-n7vwb7H/pcYmn2L6BIqHaA]![server.ccl.net> X-Original-From: "Neese, Frank" Content-Language: de-DE Content-Type: multipart/alternative; boundary="_000_3B17B7B5A4C34C4EA923B347DAF829E5cecmpgde_" Date: Sun, 10 Sep 2017 16:43:59 +0000 MIME-Version: 1.0 Sent to CCL by: "Neese, Frank" [frank.neese!=!cec.mpg.de] --_000_3B17B7B5A4C34C4EA923B347DAF829E5cecmpgde_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Dear Henrique, This is the kind of problem where you have to pay attention to the actual e= lectronic structure and not just run calculations. You have to pay attention to spin coupling. Co(III) is d6 system. Depending= on the coordination environment, the most likely local spin states are Sl= =3D0 or 1. The three local spins - if there are any - could couple to St=3D= 3,2,1 or perhaps 0. In a triangle spin frustration occurs and the coupling = is most likely antiferromagnetic which would leave St=3D1 most likely (if S= l=3D1), but it could well be more complicated if there is any orbital degen= eracy. The point is that the lower spin states are not single determinants and hen= ce just entering a given multiplicity in a DFT program and run with it is i= ncorrect. You obtain broken symmetry determinants that are eigenfunctions t= o Sz but not S**2. Spin projection techniques must then be applied to estim= ate spin state energies. A multireference method is an alternative, but you have to work hard to ove= rcome the self consistent field bias for high spin states and the underesti= mation of exchange coupling. IMHO these problems are most easily solved experimentally. Connecting to th= e experiment (susceptibility, MCD, EPR ...) is = vital in the first place. Please allow me - My coordination chemistry reviews article from 2009 provi= des a somewhat detailed discussion. From a more conceptual point of view yo= u may want to check a just published Angewandte Chemie Essay. A whole issue= of coordination chemistry rev has recently been devoted to molecular magne= tism - there generally is a rich literature on this type of problem. Good luck, Cheers, Frank Von meinem iPhone gesendet Am 10.09.2017 um 18:15 schrieb Sergio Emanuel Galembeck segalemb]-[usp.br >: Dear Henrique, I suggest that for each spin state you optimize the geometry. Some of this = states could generate an unstable geometry. Best regards, Sergio Prof. Sergio Emanuel Galembeck Computational Quantum Chemistry Laboratory Departamento de Qu=EDmica - FFCLRP-USP Av. Bandeirantes, 3900 14040-901 - Ribeirao Preto-SP Brasil phone: +55(16)33153765 segalemb~!~usp.br 2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior henriquecsj+/-gmail.com = >: Dear colleagues, I=92m working with a Cobalt(II) trimer whose molecular str= ucture was achieved by Single Crystal X-Ray Diffraction. My task now is to = check the spin states of the structure (High or Low spin). Since Co(II) can= have 1 or 3 unpaired electrons, I=92m approaching this problem by calculat= ing Single Points for every possible multiplicity (10, 8, 6, 4, 2) and assu= ming that the most stable is the one that represents my structure (and my s= pin states). Is this approach correct? Thank you -- Henrique C. S. Junior --_000_3B17B7B5A4C34C4EA923B347DAF829E5cecmpgde_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Dear Henriqu= e,

This is the = kind of problem where you have to pay attention to the actual electronic st= ructure and not just run calculations.

You have to pay attention to spin coupling. Co(III) is d6 sys= tem. Depending on the coordination environment, the most likely local spin = states are Sl=3D0 or 1. The three local spins - if there are any - could couple to St=3D3,2,1 or perhaps 0. In a t= riangle spin frustration occurs and the coupling is most likely antiferroma= gnetic which would leave St=3D1 most likely (if Sl=3D1), but it could well = be more complicated if there is any orbital degeneracy.

The point is that the lower spin states are not single determ= inants and hence just entering a given multiplicity in a DFT program and ru= n with it is incorrect. You obtain broken symmetry determinants that are eigenfunctions to Sz but not S**2. Spin pro= jection techniques must then be applied to estimate spin state energies.&nb= sp;

A multireference method is an alternative, but you have to wo= rk hard to overcome the self consistent field bias for high spin states and= the underestimation of exchange coupling.

IMHO these problems are most easily solved experimentally. Co= nnecting to the experiment (susceptibility, MCD, EPR ...) is vital in the first p= lace.

Please allow me - My coordination chemistry reviews article f= rom 2009 provides a somewhat detailed discussion. From a more conceptual po= int of view you may want to check a just published Angewandte Chemie Essay. A whole issue of coordination chem= istry rev has recently been devoted to molecular magnetism - there generall= y  is a rich literature on this type of problem.

Good luck,
Cheers,
Frank

Von meinem iPhone gesendet

Am 10.09.2017 um 18:15 schrieb Sergio Emanuel Galembeck segalemb]-[usp.br <owner-chemistry.]![.ccl.net>:

Dear Henrique,

I suggest that for each spin state you optimize the geometry. Some of = this states could generate an unstable geometry. 

Best regards,

Sergio

Prof. Sergio Emanuel Galembeck
Computational Quantum Chemistry Laboratory
Departamento de Qu=EDmica - FFCLRP-USP
Av. Bandeirantes, 3900
14040-901 - Ribeirao Preto-SP
Brasil

phone: +55(16)33153765

2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior = henriquecsj+/-gmail.com <owner-chemistry~!~ccl.net>:

Dear colleagues, I=92m working with a Cobalt(II) trime= r whose molecular structure was achieved by Single Crystal X-Ray Diffractio= n. My task now is to check the spin states of the structure (High or Low sp= in). Since Co(II) can have 1 or 3 unpaired electrons, I=92m approaching this problem by calculating Single Points for= every possible multiplicity (10, 8, 6, 4, 2) and assuming that the most st= able is the one that represents my structure (and my spin states).

Is this approach correct?

Thank you


--
Henrique C. S. Junior


--_000_3B17B7B5A4C34C4EA923B347DAF829E5cecmpgde_-- From owner-chemistry@ccl.net Sun Sep 10 16:01:00 2017 From: "Gutsev, Gennady L. gennady.gutsev],[famu.edu" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52990-170910155934-23940-rVN79bl87oA1GRUx2nLK0A_+_server.ccl.net> X-Original-From: "Gutsev, Gennady L." Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_BN6PR07MB3460655BD17862B5FD4251C4E96B0BN6PR07MB3460namp_" Date: Sun, 10 Sep 2017 19:59:26 +0000 MIME-Version: 1.0 Sent to CCL by: "Gutsev, Gennady L." [gennady.gutsev|-|famu.edu] --_000_BN6PR07MB3460655BD17862B5FD4251C4E96B0BN6PR07MB3460namp_ Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: quoted-printable Dear Henrique, please provide your e-mail address and I can send you the results (unpublis= hed) of my BPW91/6-311+G* computations. Actually, Co3 is ferromagnetic State=3D8-A'\HF=3D-4148.6131346 as well as the Co3- anion State=3D9-A"\HF=3D-4148.6665518 and the Co3+ cation State=3D7-A"\HF=3D-4148.39123 This is in line with experimental findings for larger Con clusters (as well= as their neighbor Fen and Nin clusters) Cheers, Gennady Gutsev gennady.gutsev---famu.edu ________________________________ > From: owner-chemistry+gennady.gutsev=3D=3Dfamu.edu---ccl.net on behalf of Henrique C. S. Junior h= enriquecsj+/-gmail.com Sent: Sunday, September 10, 2017 8:03:28 AM To: Gutsev, Gennady L. Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Si= ngle Points)? Dear colleagues, I=1B$B!G=1B(Bm working with a Cobalt(II) trimer whose mole= cular structure was achieved by Single Crystal X-Ray Diffraction. My task n= ow is to check the spin states of the structure (High or Low spin). Since C= o(II) can have 1 or 3 unpaired electrons, I=1B$B!G=1B(Bm approaching this p= roblem by calculating Single Points for every possible multiplicity (10, 8,= 6, 4, 2) and assuming that the most stable is the one that represents my s= tructure (and my spin states). Is this approach correct? Thank you -- Henrique C. S. Junior --_000_BN6PR07MB3460655BD17862B5FD4251C4E96B0BN6PR07MB3460namp_ Content-Type: text/html; charset="iso-2022-jp" Content-Transfer-Encoding: quoted-printable

Dear Henrique,

please provide your e-mail address and I can send you the results (unpub= lished)

of my BPW91/6-311+G* computations. Actually, Co3 is ferromagnet= ic

State=3D8-A'\HF=3D-4148.6131346 as well as the Co3- anion

State=3D9-A"\HF=3D-4148.6665518   and the Co3+ cation

State=3D7-A"\HF=3D-4148.39123

This is in line with experimental findings for larger Con clusters (as well as = their

neighbor Fen and Nin clusters)

Cheers,

Gennady Gutsev

gennady.gutsev---famu.edu 

From: owner-chemistry+g= ennady.gutsev=3D=3Dfamu.edu---ccl.net <owner-chemistry+gennady.gutsev= =3D=3Dfamu.edu---ccl.net> on behalf of Henrique C. S. Junior henriquecsj&#= 43;/-gmail.com <owner-chemistry---ccl.net>
Sent: Sunday, September 10, 2017 8:03:28 AM
To: Gutsev, Gennady L.
Subject: CCL: Correctly evaluating spin states of a cobalt trimer (u= sing Single Points)?
 

Dear colleagues, I=1B$B!G=1B(Bm working with a Cobalt(= II) trimer whose molecular structure was achieved by Single Crystal X-Ray D= iffraction. My task now is to check the spin states of the structure (High = or Low spin). Since Co(II) can have 1 or 3 unpaired electrons, I=1B$B!G=1B(Bm approaching this problem by calculating Single P= oints for every possible multiplicity (10, 8, 6, 4, 2) and assuming that th= e most stable is the one that represents my structure (and my spin states).=

Is this approach correct?

Thank you


--
Henrique C. S. Junior

--_000_BN6PR07MB3460655BD17862B5FD4251C4E96B0BN6PR07MB3460namp_-- From owner-chemistry@ccl.net Sun Sep 10 16:36:00 2017 From: "Henrique C. S. Junior henriquecsj|,|gmail.com" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52991-170910160343-26337-RliFQ4ND2HEr5umZAMOCFA**server.ccl.net> X-Original-From: "Henrique C. S. Junior" Content-Type: multipart/alternative; boundary="001a113ff1924124720558db4eca" Date: Sun, 10 Sep 2017 17:02:56 -0300 MIME-Version: 1.0 Sent to CCL by: "Henrique C. S. Junior" [henriquecsj=-=gmail.com] --001a113ff1924124720558db4eca Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Professor Neese, thank you for your kind reply and pointing me to your review; that was really helpful. All the best. On Sun, Sep 10, 2017 at 1:43 PM, Neese, Frank frank.neese * cec.mpg.de < owner-chemistry^ccl.net> wrote: > Dear Henrique, > > This is the kind of problem where you have to pay attention to the actual > electronic structure and not just run calculations. > > You have to pay attention to spin coupling. Co(III) is d6 system. > Depending on the coordination environment, the most likely local spin > states are Sl=3D0 or 1. The three local spins - if there are any - could > couple to St=3D3,2,1 or perhaps 0. In a triangle spin frustration occurs = and > the coupling is most likely antiferromagnetic which would leave St=3D1 mo= st > likely (if Sl=3D1), but it could well be more complicated if there is any > orbital degeneracy. > > The point is that the lower spin states are not single determinants and > hence just entering a given multiplicity in a DFT program and run with it > is incorrect. You obtain broken symmetry determinants that are > eigenfunctions to Sz but not S**2. Spin projection techniques must then b= e > applied to estimate spin state energies. > > A multireference method is an alternative, but you have to work hard to > overcome the self consistent field bias for high spin states and the > underestimation of exchange coupling. > > IMHO these problems are most easily solved experimentally. Connecting to = the > experiment (susceptibility, MCD, EPR ...) is vital in the first place. > > Please allow me - My coordination chemistry reviews article from 2009 > provides a somewhat detailed discussion. From a more conceptual point of > view you may want to check a just published Angewandte Chemie Essay. A > whole issue of coordination chemistry rev has recently been devoted to > molecular magnetism - there generally is a rich literature on this type = of > problem. > > Good luck, > Cheers, > Frank > > Von meinem iPhone gesendet > > Am 10.09.2017 um 18:15 schrieb Sergio Emanuel Galembeck segalemb]-[usp.br > : > > Dear Henrique, > > I suggest that for each spin state you optimize the geometry. Some of thi= s > states could generate an unstable geometry. > > Best regards, > > Sergio > > Prof. Sergio Emanuel Galembeck > Computational Quantum Chemistry Laboratory > Departamento de Qu=C3=ADmica - FFCLRP-USP > Av. Bandeirantes, 3900 > > 14040-901 - Ribeirao Preto-SP > Brasil > > phone: +55(16)33153765 <(16)%203315-3765> > segalemb~!~usp.br > > 2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior henriquecsj+/-gmail.com < > owner-chemistry~!~ccl.net>: > >> Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose mole= cular >> structure was achieved by Single Crystal X-Ray Diffraction. My task now = is >> to check the spin states of the structure (High or Low spin). Since Co(I= I) >> can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem= by >> calculating Single Points for every possible multiplicity (10, 8, 6, 4, = 2) >> and assuming that the most stable is the one that represents my structur= e >> (and my spin states). >> >> Is this approach correct? >> >> Thank you >> >> -- >> *Henrique C. S. Junior* >> >> > --=20 *Henrique C. S. Junior* --001a113ff1924124720558db4eca Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear Professor Neese, thank you for your kind reply and pointi= ng me to your review; that was really helpful.

All the best.

On Sun, Sep 10, 201= 7 at 1:43 PM, Neese, Frank frank.neese * cec.= mpg.de <owner-chemistry^ccl.net> wrote:
Dear Henrique,

This is the kind = of problem where you have to pay attention to the actual electronic structu= re and not just run calculations.

You have to pay attention to spin coupling. C= o(III) is d6 system. Depending on the coordination environment, the most li= kely local spin states are Sl=3D0 or 1. The three local spins - if there are any - could couple to St=3D3,2,1 or perhaps 0. In a t= riangle spin frustration occurs and the coupling is most likely antiferroma= gnetic which would leave St=3D1 most likely (if Sl=3D1), but it could well = be more complicated if there is any orbital degeneracy.

The point is that the lower spin states are n= ot single determinants and hence just entering a given multiplicity in a DF= T program and run with it is incorrect. You obtain broken symmetry determinants that are eigenfunctions to Sz but not S**2. Spin pro= jection techniques must then be applied to estimate spin state energies.=C2= =A0

A multireference method is an alternative, bu= t you have to work hard to overcome the self consistent field bias for high= spin states and the underestimation of exchange coupling.

IMHO these problems are most easily solved ex= perimentally. Connecting to=C2=A0the experiment=C2=A0(susceptibility, MCD, EPR ...) is vital in the first p= lace.

Please allow me - My coordination chemistry r= eviews article from 2009 provides a somewhat detailed discussion. From a mo= re conceptual point of view you may want to check a just published Angewandte Chemie Essay. A whole issue of coordination chem= istry rev has recently been devoted to molecular magnetism - there generall= y =C2=A0is a rich literature on this type of problem.

Good luck,
Cheers,
Frank

Von meinem iPhone gesendet

Am 10.09.2017 um 18:15 schrieb Sergio Emanuel Galembeck segalemb]-[usp.br <owner-chemistry(~)ccl.net>:<= br>
Dear Henrique,

I suggest that for each spin state you optimize the geometry. Some of = this states could generate an unstable geometry.=C2=A0

Best regards,

Sergio

Prof. Sergio Emanuel Galembeck
Computational Quantum Chemistry Laboratory
Departamento de Qu=C3=ADmica - FFCLRP-USP
14040-901 - Ribeirao Preto-SP
Brasil


2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior = henriquecsj+/-gmail.com <owner-chemistry~!~ccl.net>:

Dear colleagues, I=E2=80=99m working with a Cobalt(II)= trimer whose molecular structure was achieved by Single Crystal X-Ray Diff= raction. My task now is to check the spin states of the structure (High or = Low spin). Since Co(II) can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem by calculating Single Poin= ts for every possible multiplicity (10, 8, 6, 4, 2) and assuming that the m= ost stable is the one that represents my structure (and my spin states).

Is this approach correct?

Thank you


--
Henrique C. S. Junior





--
Henri= que C. S. Junior

--001a113ff1924124720558db4eca-- From owner-chemistry@ccl.net Sun Sep 10 19:08:01 2017 From: "Sergio Emanuel Galembeck segalemb]![usp.br" To: CCL Subject: CCL: Correctly evaluating spin states of a cobalt trimer (using Single Points)? Message-Id: <-52992-170910190638-5986-VPdY2SS1c3oXuyosVmdMkw~!~server.ccl.net> X-Original-From: Sergio Emanuel Galembeck Content-Type: multipart/alternative; boundary="f403045e259c6161270558dddc45" Date: Sun, 10 Sep 2017 20:06:31 -0300 MIME-Version: 1.0 Sent to CCL by: Sergio Emanuel Galembeck [segalemb]*[usp.br] --f403045e259c6161270558dddc45 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Henrique, I am not entirely sure if a single point is correct for study magnetic couplings. Normally, a geometry optimization is the first step for an isolated system, because the experimental minimum is not the same as a computational quantum chemistry one. But, I think that your main concern is the broken symmetry problem and the multiconfigurational character of the wavefunction. Unfortunately, I don't work with these problems and techniques, but I can indicate some Brazilian theoretical chemists that work with these subjects, or at least with multiconfigurational methods. Best regards, Sergio Prof. Sergio Emanuel Galembeck Computational Quantum Chemistry Laboratory Departamento de Qu=C3=ADmica - FFCLRP-USP Av. Bandeirantes, 3900 14040-901 - Ribeirao Preto-SP Brasil phone: +55(16)33153765 segalemb]*[usp.br 2017-09-10 13:21 GMT-03:00 Henrique C. S. Junior henriquecsj,+,gmail.com < owner-chemistry]*[ccl.net>: > Dear Sergio, thanks for your reply. I forgot to tell that this structure > is to be used to study magnetic couplings, so we usually don't perform > geometry optimizations. > Despite that, do you believe that the Single Points approach is, in > general, correct? > > On Sun, Sep 10, 2017 at 11:07 AM, Sergio Emanuel Galembeck segalemb]-[ > usp.br wrote: > >> Dear Henrique, >> >> I suggest that for each spin state you optimize the geometry. Some of >> this states could generate an unstable geometry. >> >> Best regards, >> >> Sergio >> >> Prof. Sergio Emanuel Galembeck >> Computational Quantum Chemistry Laboratory >> Departamento de Qu=C3=ADmica - FFCLRP-USP >> Av. Bandeirantes, 3900 >> >> 14040-901 - Ribeirao Preto-SP >> Brasil >> >> phone: +55(16)33153765 <(16)%203315-3765> >> segalemb~!~usp.br >> >> 2017-09-10 9:03 GMT-03:00 Henrique C. S. Junior henriquecsj+/-gmail.com = < >> owner-chemistry~!~ccl.net>: >> >>> Dear colleagues, I=E2=80=99m working with a Cobalt(II) trimer whose mol= ecular >>> structure was achieved by Single Crystal X-Ray Diffraction. My task now= is >>> to check the spin states of the structure (High or Low spin). Since Co(= II) >>> can have 1 or 3 unpaired electrons, I=E2=80=99m approaching this proble= m by >>> calculating Single Points for every possible multiplicity (10, 8, 6, 4,= 2) >>> and assuming that the most stable is the one that represents my structu= re >>> (and my spin states). >>> >>> Is this approach correct? >>> >>> Thank you >>> >>> -- >>> *Henrique C. S. Junior* >>> >>> >> > > > -- > *Henrique C. S. Junior* > Industrial Chemist - UFRRJ > M. Sc. Inorganic Chemistry - UFRRJ > Data Processing Center - PMP > Visite o Mundo Qu=C3=ADmico > --f403045e259c6161270558dddc45 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear Henrique,

I am not entirely sure i= f a single point is correct for study magnetic couplings. Normally, a geome= try optimization is the first step for an
isolated system, because the= experimental minimum is not the same as
a computational quantum chemis= try one.

But, I think that your main concern is th= e broken symmetry problem and the multiconfigurational character of the wav= efunction.=C2=A0

Unfortunately, I don't work w= ith these problems and techniques, but I can indicate
some Brazilian t= heoretical chemists that work with these subjects, or at least with multico= nfigurational
methods.=C2=A0

Best regards,

Sergio


Prof. Sergio Emanuel = Galembeck
Computational Quantum Chemistry Laboratory<= br>
Departamento de Qu=C3=ADmica - FFCLRP-USP
Av. Bandeirante= s, 3900
14040-901 - Ribeirao Preto-SP
Brasil
=
phone: +55(16)33153765

2017-09-10 13:21 GMT-03:00 Henrique C. S. Ju= nior henriquecsj,+,gmail.com <owner-chemistry]*[ccl.net= >:
Dear Sergio, thanks for your reply.= I forgot to tell that this structure is to be used to study magnetic coupl= ings, so we usually don't perform geometry optimizations.
Despite that, do you believe that th= e Single Points approach is, in general, correct?

On Sun, Sep 10= , 2017 at 11:07 AM, Sergio Emanuel Galembeck segalemb]-[usp.br <owner-chemistry__ccl.net> wrote:
Dear Henrique,
=
I suggest that for each spin state you optimize the geometry= . Some of this states could generate an unstable geometry.=C2=A0
=
Best regards,

Sergio

Prof. Ser= gio Emanuel Galembeck
Computational Quantum Chemistry= Laboratory
Departamento de Qu=C3=ADmica - FFCLRP-USP
14040-901 - Ribeira= o Preto-SP
Brasil


2017-09-10 9:03 GMT-03:00 Henrique C. S. Jun= ior henriquecsj+/-gmail.com <owner-chemistry~!~ccl.= net>:

Dear c= olleagues, I=E2=80=99m working with a Cobalt(II) trimer whose molecular str= ucture was achieved by Single Crystal X-Ray Diffraction. My task now is to = check the spin states of the structure (High or Low spin). Since Co(II) can= have 1 or 3 unpaired electrons, I=E2=80=99m approaching this problem by ca= lculating Single Points for every possible multiplicity (10, 8, 6, 4, 2) an= d assuming that the most stable is the one that represents my structure (an= d my spin states).

Is this approach correct?

Thank you


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<= div class=3D"m_6743374104478720003m_95474415170385095m_-6950408394098624088= gmail_signature">
Henrique C. S. Junior





--
<= div dir=3D"ltr">
Henrique C. S. Junior
Ind= ustrial Chemist - UFRRJ
M. Sc. Inorgani= c Chemistry - UFRRJ
Data Processing Center - PMP
=
<= /div>
--f403045e259c6161270558dddc45--