From owner-chemistry@ccl.net Wed Sep 4 07:17:00 2019 From: "Mariusz Radon mariusz.radon%%gmail.com" To: CCL Subject: CCL:G: Structure breaks even after started with correct bond length Message-Id: <-53826-190904071604-18072-pipoh2QhP8hfcb/fk07DXA-.-server.ccl.net> X-Original-From: Mariusz Radon Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=utf-8 Date: Wed, 4 Sep 2019 13:15:55 +0200 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Sent to CCL by: Mariusz Radon [mariusz.radon.:.gmail.com] > On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com wrote: > > > Sent to CCL by: "Nikhil Maroli" [scinikhil(0)gmail.com] > Dear all users and experts, > > I have modelled cubic structure Cs based quantum dot (perovskite) with > correct bond length between Cs-Br and Pb-Br atoms.After few steps of > optimisation the bond length increases and structure is completely broken. > I am using Gaussian 09 and started with HF (planned to do B3LYP). can > anyone help me to solve the issue. > Dear Nikhil: If you are using an ECP basis set (Pb, Br atoms?), make sure the correct pseudopotential has been read correctly. If you accidentally made such an error (i.e., starting calculations with an ECP-optimized basis set without actually reading in the pseudopotential), Gaussian would not complain, and even (if you are “lucky”) you might be able to converge the SCF - obviously to something very, very unreasonable, so that your geometry will quickly get broken during the optimization. Best wishes, Mariusz> > -- Mariusz Radon, Ph.D. Faculty of Chemistry Jagiellonian University ul. Ingardena 3 30-060 Krakow, Poland e-mail: mradon/a\chemia.uj.edu.pl or mariusz.radon/a\uj.edu.pl web: http://www.chemia.uj.edu.pl/~mradon ORCID: https://orcid.org/0000-0002-1901-8521 From owner-chemistry@ccl.net Wed Sep 4 07:52:00 2019 From: "Nikhil Maroli scinikhil .. gmail.com" To: CCL Subject: CCL:G: Structure breaks even after started with correct bond length Message-Id: <-53827-190904072250-19992-GF/XkOYaB1chqkaUnM2DJg(a)server.ccl.net> X-Original-From: Nikhil Maroli Content-Type: multipart/alternative; boundary="000000000000610b810591b86c05" Date: Wed, 4 Sep 2019 16:52:01 +0530 MIME-Version: 1.0 Sent to CCL by: Nikhil Maroli [scinikhil^gmail.com] --000000000000610b810591b86c05 Content-Type: text/plain; charset="UTF-8" Hi, I have started with MP2 with the following title # opt freq=noraman mp2/lanl2dz geom=connectivity it ended up with an error as below Largest valence mixing into a core orbital is 4.37D-01 Largest core mixing into a valence orbital is 3.40D-01 Excessive mixing of frozen core and valence orbitals. Then I have modified the tile to this after searching over the archives # opt freq=noraman ump2=full/lanl2mb scf=qc geom=connectivity Which ended up in a broken structure. Can anyone help me out here? On Wed, Sep 4, 2019 at 5:07 AM Salter-Duke, Brian James brian.james.duke]*[gmail.com wrote: > > Sent to CCL by: "Salter-Duke, Brian James " [brian.james.duke,, > gmail.com] > Well, HF is a pretty poor approximation and maybe it does fall apart at > HF. Try > DFT but use somehting better than the old B3LYP, and then try MP2. > > On Tue, Sep 03, 2019 at 10:34:21AM -0400, Nikhil Maroli scinikhila/ > gmail.com wrote: > > > > Sent to CCL by: "Nikhil Maroli" [scinikhil(0)gmail.com] > > Dear all users and experts, > > > > I have modelled cubic structure Cs based quantum dot (perovskite) with > > correct bond length between Cs-Br and Pb-Br atoms.After few steps of > > optimisation the bond length increases and structure is completely > broken. > > I am using Gaussian 09 and started with HF (planned to do B3LYP). can > > anyone help me to solve the issue.> > > -- > Brian Salter-Duke (Brian Duke) Brian.Salter-Duke{=}monash.edu > Adjunct Associate Professor > Monash Institute of Pharmaceutical Sciences > Monash University Parkville Campus, VIC 3052, Australia> > > -- Regards, Nikhil Maroli --000000000000610b810591b86c05 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi,

I have started with MP2 with the fo= llowing title
# opt freq=3Dnoraman mp2/lanl2dz geom=3Dconnectivit= y

it ended up with an error as below
=C2=A0Largest valence mixing into a core orbital is =C2=A04.37D-01
=C2= =A0Largest core mixing into a valence orbital is =C2=A03.40D-01
=C2=A0Ex= cessive mixing of frozen core and valence orbitals.

Then I have modified the tile to this after searching over the archiv= es
# opt freq=3Dnoraman ump2=3Dfull/lanl2mb scf=3Dqc geom=3Dconne= ctivity

Which ended up in a broken structure.<= /div>
Can anyone help me out here?


<= /div>
O= n Wed, Sep 4, 2019 at 5:07 AM Salter-Duke, Brian James brian.james= .duke]*[gmail.com <owner-chemistry]_[ccl.net> wrote:

Sent to CCL by: "Salter-Duke, Brian James " [brian.james.= duke,,gma= il.com]
Well, HF is a pretty poor approximation and maybe it does fall apart at HF.= Try
DFT but use somehting better than the old B3LYP, and then try MP2.

On Tue, Sep 03, 2019 at 10:34:21AM -0400, Nikhil Maroli scinikhila/gmail.com wr= ote:
>
> Sent to CCL by: "Nikhil=C2=A0 Maroli" [scinikhil(0)gmail.com] > Dear all users and experts,
>
> I have modelled cubic structure Cs based quantum dot (perovskite) with=
> correct bond length between Cs-Br and Pb-Br atoms.After few steps of <= br> > optimisation the bond length increases and structure is completely bro= ken.
> I am using Gaussian 09 and started with HF (planned to do B3LYP). can =
> anyone help me to solve the issue.>

--
=C2=A0 =C2=A0Brian Salter-Duke (Brian Duke)=C2=A0 =C2=A0Brian.Salter-Duke{= =3D}mona= sh.edu
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Adjun= ct Associate Professor
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 Monash Institute of Pharmaceutica= l Sciences
=C2=A0 =C2=A0 =C2=A0 Monash University Parkville Campus, VIC 3052, Australi= a



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--
Rega= rds,
Nikhil Maroli

--000000000000610b810591b86c05-- From owner-chemistry@ccl.net Wed Sep 4 09:07:01 2019 From: "Nikhil Maroli scinikhil*o*gmail.com" To: CCL Subject: CCL:G: Structure breaks even after started with correct bond length Message-Id: <-53828-190904090543-8204-+2qddkiM/kaSHNq/67bhLQ**server.ccl.net> X-Original-From: Nikhil Maroli Content-Type: multipart/alternative; boundary="00000000000077f7030591b9dcf4" Date: Wed, 4 Sep 2019 18:34:57 +0530 MIME-Version: 1.0 Sent to CCL by: Nikhil Maroli [scinikhil+/-gmail.com] --00000000000077f7030591b9dcf4 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Thank you very much for your reply Mariusz, Which basis set you to suggest for Cs, Pb and Br atom. ? (Quantum dot) Sorry, im new to Gaussian or quantum chemistry calculations. On Wed, Sep 4, 2019 at 6:10 PM Mariusz Radon mariusz.radon%%gmail.com < owner-chemistry- -ccl.net> wrote: > > Sent to CCL by: Mariusz Radon [mariusz.radon.:.gmail.com] > > > On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com > wrote: > > > > > > Sent to CCL by: "Nikhil Maroli" [scinikhil(0)gmail.com] > > Dear all users and experts, > > > > I have modelled cubic structure Cs based quantum dot (perovskite) with > > correct bond length between Cs-Br and Pb-Br atoms.After few steps of > > optimisation the bond length increases and structure is completely > broken. > > I am using Gaussian 09 and started with HF (planned to do B3LYP). can > > anyone help me to solve the issue. > > > > Dear Nikhil: > > If you are using an ECP basis set (Pb, Br atoms?), make sure the correct > pseudopotential has been read correctly. If you accidentally made such an > error (i.e., starting calculations with an ECP-optimized basis set withou= t > actually reading in the pseudopotential), Gaussian would not complain, an= d > even (if you are =E2=80=9Clucky=E2=80=9D) you might be able to converge t= he SCF - obviously > to something very, very unreasonable, so that your geometry will quickly > get broken during the optimization. > > Best wishes, > Mariusz> > > > > -- > Mariusz Radon, Ph.D. > Faculty of Chemistry > Jagiellonian University > ul. Ingardena 3 > 30-060 Krakow, Poland > > e-mail: mradon _ chemia.uj.edu.pl > or mariusz.radon _ uj.edu.pl > web: http://www.chemia.uj.edu.pl/~mradon > ORCID: https://orcid.org/0000-0002-1901-8521 > > > > -=3D This is automatically added to each message by the mailing script = =3D-> > > --=20 Regards, Nikhil Maroli --00000000000077f7030591b9dcf4 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Thank you very much for your reply=C2=A0 Mariusz,

Which basis set you to suggest for Cs, Pb and B= r atom. ? (Quantum dot) Sorry, im new to Gaussian or quantum chemistry calc= ulations.

On Wed, Sep 4, 2019 at 6:10 PM Mariusz Radon mariusz.radon%= %gmail.com <owner-chemistry- -ccl.n= et> wrote:
gmail.com]

> On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com <owner-chem= istry _ ccl= .net> wrote:
>
>
> Sent to CCL by: "Nikhil=C2=A0 Maroli" [scinikhil(0)gmail.com] > Dear all users and experts,
>
> I have modelled cubic structure Cs based quantum dot (perovskite) with=
> correct bond length between Cs-Br and Pb-Br atoms.After few steps of <= br> > optimisation the bond length increases and structure is completely bro= ken.
> I am using Gaussian 09 and started with HF (planned to do B3LYP). can =
> anyone help me to solve the issue.
>

Dear Nikhil:

If you are using an ECP basis set (Pb, Br atoms?), make sure the correct ps= eudopotential has been read correctly. If you accidentally made such an err= or (i.e., starting calculations with an ECP-optimized basis set without act= ually reading in the pseudopotential), Gaussian would not complain, and eve= n (if you are =E2=80=9Clucky=E2=80=9D) you might be able to converge the SC= F - obviously to something very, very unreasonable, so that your geometry w= ill quickly get broken during the optimization.

Best wishes,
Mariusz>
>

--
Mariusz Radon, Ph.D.
Faculty of Chemistry
Jagiellonian University
ul. Ingardena 3
30-060 Krakow, Poland

e-mail: mradon _ chemia.uj.edu.pl
or mariusz.radon _ uj.edu.pl
web: http://www.chemia.uj.edu.pl/~mradon
ORCID:=C2=A0 https://orcid.org/0000-0002-1901-8521



-=3D This is automatically added to each message by the mailing script =3D-=
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--
Regards,
Nikhil Maroli

--00000000000077f7030591b9dcf4-- From owner-chemistry@ccl.net Wed Sep 4 11:28:00 2019 From: "Uche Anene uche=uconn.edu" To: CCL Subject: CCL:G: Structure breaks even after started with correct bond length Message-Id: <-53829-190904112701-25920-S5C7zrNjV0bzhM9dwgPLXQ**server.ccl.net> X-Original-From: Uche Anene Content-Type: multipart/alternative; boundary="Apple-Mail=_5B4E4010-5F2C-4BB2-9E8B-3744218F61D2" Date: Wed, 4 Sep 2019 11:26:54 -0400 Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Sent to CCL by: Uche Anene [uche!^!uconn.edu] --Apple-Mail=_5B4E4010-5F2C-4BB2-9E8B-3744218F61D2 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hi Nikhil, Choosing the correct basis set really depends on you. You are = essentially asking what level of accuracy you willing to accept or is = acceptable for your model. That is a question only you can answer. For = that, I recommend looking through literature to see what method and = basis set is acceptable for your model/scientific question. Your are asking questions that are beyond Gaussian error issues. You = should take a step back and read more literature to try to understand = what you are doing and what you are trying to achieve. You may discover = that it is acceptable to freeze some of the atoms during optimization. For information on basis set, I recommend going through the Gaussian = manual: https://gaussian.com/basissets/ Happy computing, Uche --- Uchenna A. Anene Ph.D. Student, Chemical Engineering =20 University of Connecticut Innovation Partnership Building=20 159 Discovery Drive Storrs, CT 06269 uche * uconn.edu https://alpay.ims.uconn.edu/uche-anene/# www.linkedin.com/in/uche-anene =20= https://www.researchgate.net/profile/Uchenna_Anene = > On Sep 4, 2019, at 9:04 AM, Nikhil Maroli scinikhil*o*gmail.com = wrote: >=20 > Thank you very much for your reply Mariusz, >=20 > Which basis set you to suggest for Cs, Pb and Br atom. ? (Quantum dot) = Sorry, im new to Gaussian or quantum chemistry calculations. >=20 > On Wed, Sep 4, 2019 at 6:10 PM Mariusz Radon mariusz.radon%%gmail.com = > wrote: >=20 > Sent to CCL by: Mariusz Radon [mariusz.radon.:.gmail.com = ] >=20 > > On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com = > wrote: > >=20 > >=20 > > Sent to CCL by: "Nikhil Maroli" [scinikhil(0)gmail.com = ] > > Dear all users and experts, > >=20 > > I have modelled cubic structure Cs based quantum dot (perovskite) = with=20 > > correct bond length between Cs-Br and Pb-Br atoms.After few steps of=20= > > optimisation the bond length increases and structure is completely = broken.=20 > > I am using Gaussian 09 and started with HF (planned to do B3LYP). = can=20 > > anyone help me to solve the issue. > >=20 >=20 > Dear Nikhil: >=20 > If you are using an ECP basis set (Pb, Br atoms?), make sure the = correct pseudopotential has been read correctly. If you accidentally = made such an error (i.e., starting calculations with an ECP-optimized = basis set without actually reading in the pseudopotential), Gaussian = would not complain, and even (if you are =E2=80=9Clucky=E2=80=9D) you = might be able to converge the SCF - obviously to something very, very = unreasonable, so that your geometry will quickly get broken during the = optimization. >=20 > Best wishes, > Mariusz>=20 > >=20 >=20 > --=20 > Mariusz Radon, Ph.D. > Faculty of Chemistry > Jagiellonian University > ul. Ingardena 3 > 30-060 Krakow, Poland >=20 > e-mail: mradon _ chemia.uj.edu.pl =20 > or mariusz.radon _ uj.edu.pl > web: http://www.chemia.uj.edu.pl/~mradon = > ORCID: https://orcid.org/0000-0002-1901-8521 = >=20 >=20 >=20 > -=3D This is automatically added to each message by the mailing script = =3D- >=20 >=20 >=20 > E-mail to subscribers: CHEMISTRY++ccl.net = or use:= >=20 > E-mail to administrators: CHEMISTRY-REQUEST++ccl.net = or use= >=20 >=20= >=20= >=20=20 > Conferences: = http://server.ccl.net/chemistry/announcements/conferences/ = >=20= >=20 >=20= >=20= >=20 >=20 >=20 >=20 > --=20 > Regards, > Nikhil Maroli >=20 --Apple-Mail=_5B4E4010-5F2C-4BB2-9E8B-3744218F61D2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Hi = Nikhil,

Choosing the = correct basis set really depends on you. You are essentially asking what = level of accuracy you willing to accept or is acceptable for your model. = That is a question only you can answer. For that, I recommend looking = through literature to see what method and basis set is acceptable for = your model/scientific question.

Your are asking questions that are = beyond Gaussian error issues. You should take a step back and read more = literature to try to understand what you are doing and what you are = trying to achieve. You may discover that it is acceptable to freeze some = of the atoms during optimization.

For information on basis set, I = recommend going through the Gaussian manual:
https://gaussian.com/basissets/

Happy computing,
Uche


---
Uchenna A. Anene
Ph.D. Student, Chemical Engineering =  
University of = Connecticut
Innovation Partnership = Building 
159 Discovery = Drive
Storrs, CT = 06269
uche * uconn.edu
https://alpay.ims.uconn.edu/uche-anene/#
www.linkedin.com/in/uche-anene 
https://www.researchgate.net/profile/Uchenna_Anene









On Sep 4, 2019, at 9:04 AM, Nikhil Maroli scinikhil*o*gmail.com <owner-chemistry * ccl.net> wrote:

Thank you very much for your reply  Mariusz,

Which basis = set you to suggest for Cs, Pb and Br atom. ? (Quantum dot) Sorry, im new = to Gaussian or quantum chemistry calculations.

On Wed, Sep 4, 2019 at 6:10 PM Mariusz Radon = mariusz.radon%%gmail.com <owner-chemistry++ccl.net> wrote:

Sent to CCL by: Mariusz Radon [mariusz.radon.:.gmail.com]

> On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com <owner-chemistry _ ccl.net> = wrote:
>
>
> Sent to CCL by: "Nikhil  Maroli" [scinikhil(0)gmail.com]
> Dear all users and experts,
>
> I have modelled cubic structure Cs based quantum dot (perovskite) = with
> correct bond length between Cs-Br and Pb-Br atoms.After few steps = of
> optimisation the bond length increases and structure is completely = broken.
> I am using Gaussian 09 and started with HF (planned to do B3LYP). = can
> anyone help me to solve the issue.
>

Dear Nikhil:

If you are using an ECP basis set (Pb, Br atoms?), make sure the correct = pseudopotential has been read correctly. If you accidentally made such = an error (i.e., starting calculations with an ECP-optimized basis set = without actually reading in the pseudopotential), Gaussian would not = complain, and even (if you are =E2=80=9Clucky=E2=80=9D) you might be = able to converge the SCF - obviously to something very, very = unreasonable, so that your geometry will quickly get broken during the = optimization.

Best wishes,
Mariusz>
>

--
Mariusz Radon, Ph.D.
Faculty of Chemistry
Jagiellonian University
ul. Ingardena 3
30-060 Krakow, Poland

e-mail: mradon _ chemia.uj.edu.pl
or mariusz.radon _ uj.edu.pl
web: http://www.chemia.uj.edu.pl/~mradon
ORCID:  https://orcid.org/0000-0002-1901-8521



-=3D This is automatically added to each message by the mailing script = =3D-



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      http://www.ccl.net/cgi-bin/ccl/send_ccl_message


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=
Before posting, check wait time at: http://www.ccl.net

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--
Regards,
Nikhil Maroli


= --Apple-Mail=_5B4E4010-5F2C-4BB2-9E8B-3744218F61D2-- From owner-chemistry@ccl.net Wed Sep 4 13:19:00 2019 From: "Laurence Patrick Cuffe cuffe(a)mac.com" To: CCL Subject: CCL: Structure breaks even after started with correct bond length Message-Id: <-53830-190904032836-27906-Ovk+MVqsl0l6ZmSugkDIhw|a|server.ccl.net> X-Original-From: "Laurence Patrick Cuffe" Date: Wed, 4 Sep 2019 03:28:34 -0400 Sent to CCL by: "Laurence Patrick Cuffe" [cuffe|*|mac.com] What basis set are you using? Also its worth being aware that a periodic structure is not going to be the same as an isolated molecule due to edge effects. Best Dr. Laurence Cuffe From owner-chemistry@ccl.net Wed Sep 4 13:54:00 2019 From: "Nikhil Maroli scinikhil!=!gmail.com" To: CCL Subject: CCL:G: Structure breaks even after started with correct bond length Message-Id: <-53831-190904134647-9099-B4+wEyn9aMHTKa+dUEzhBw[A]server.ccl.net> X-Original-From: Nikhil Maroli Content-Type: multipart/alternative; boundary="0000000000009ef7d30591bdc902" Date: Wed, 4 Sep 2019 23:16:00 +0530 MIME-Version: 1.0 Sent to CCL by: Nikhil Maroli [scinikhil,,gmail.com] --0000000000009ef7d30591bdc902 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi, There are no studies available on this structure ( the structure also not reported yet). The available calculations were performed using the CP2K package with mixed Gaussian and plane-wave basis set, using the molecularly optimized MOLOPT double f-valence polarized (mDZVP) basis set implemented in CP2K code. Im not asking for a basis set for my study. I have used B3LYP, CCSD and MP2 function with different basis set to obtain an optimization geometry. I ended up with different errors and the structure is broken at the end. I came to know the possibility of freezing the coordinates, but at the same time, there is suggestion that the freezing is unrealistic and may not be accurate. So in a nutshell, information from anyone who had a similar situation which is resolved would be helpful for me. Thank you for the help On Wed, Sep 4, 2019 at 10:09 PM Uche Anene uche=3Duconn.edu < owner-chemistry]*[ccl.net> wrote: > Hi Nikhil, > > Choosing the correct basis set really depends on you. You are essentially > asking what level of accuracy you willing to accept or is acceptable for > your model. That is a question only you can answer. For that, I recommend > looking through literature to see what method and basis set is acceptable > for your model/scientific question. > > Your are asking questions that are beyond Gaussian error issues. You > should take a step back and read more literature to try to understand wha= t > you are doing and what you are trying to achieve. You may discover that i= t > is acceptable to freeze some of the atoms during optimization. > > For information on basis set, I recommend going through the Gaussian > manual: > https://gaussian.com/basissets/ > > Happy computing, > Uche > > > --- > Uchenna A. Anene > Ph.D. Student, Chemical Engineering > University of Connecticut > Innovation Partnership Building > 159 Discovery Drive > Storrs, CT 06269 > uche,,uconn.edu > https://alpay.ims.uconn.edu/uche-anene/# > www.linkedin.com/in/uche-anene > https://www.researchgate.net/profile/Uchenna_Anene > > > > > > > > > > On Sep 4, 2019, at 9:04 AM, Nikhil Maroli scinikhil*o*gmail.com < > owner-chemistry,,ccl.net> wrote: > > Thank you very much for your reply Mariusz, > > Which basis set you to suggest for Cs, Pb and Br atom. ? (Quantum dot) > Sorry, im new to Gaussian or quantum chemistry calculations. > > On Wed, Sep 4, 2019 at 6:10 PM Mariusz Radon mariusz.radon%%gmail.com < > owner-chemistry++ccl.net> wrote: > >> >> Sent to CCL by: Mariusz Radon [mariusz.radon.:.gmail.com] >> >> > On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com >> wrote: >> > >> > >> > Sent to CCL by: "Nikhil Maroli" [scinikhil(0)gmail.com] >> > Dear all users and experts, >> > >> > I have modelled cubic structure Cs based quantum dot (perovskite) with >> > correct bond length between Cs-Br and Pb-Br atoms.After few steps of >> > optimisation the bond length increases and structure is completely >> broken. >> > I am using Gaussian 09 and started with HF (planned to do B3LYP). can >> > anyone help me to solve the issue. >> > >> >> Dear Nikhil: >> >> If you are using an ECP basis set (Pb, Br atoms?), make sure the correct >> pseudopotential has been read correctly. If you accidentally made such a= n >> error (i.e., starting calculations with an ECP-optimized basis set witho= ut >> actually reading in the pseudopotential), Gaussian would not complain, a= nd >> even (if you are =E2=80=9Clucky=E2=80=9D) you might be able to converge = the SCF - obviously >> to something very, very unreasonable, so that your geometry will quickly >> get broken during the optimization. >> >> Best wishes, >> Mariusz> >> > >> >> -- >> Mariusz Radon, Ph.D. >> Faculty of Chemistry >> Jagiellonian University >> ul. Ingardena 3 >> 30-060 Krakow, Poland >> >> e-mail: mradon _ chemia.uj.edu.pl >> or mariusz.radon _ uj.edu.pl >> web: http://www.chemia.uj.edu.pl/~mradon >> ORCID: https://orcid.org/0000-0002-1901-8521 >> >> >> >> -=3D This is automatically added to each message by the mailing script = =3D- >> >> >> >> E-mail to subscribers: CHEMISTRY++ccl.net or use:>> >> E-mail to administrators: CHEMISTRY-REQUEST++ccl.net or use>> >> >> > > -- > Regards, > Nikhil Maroli > > > --=20 Regards, Nikhil Maroli --0000000000009ef7d30591bdc902 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi,
There are no studies available on this structure (= the structure also not reported yet). The available calculations were perf= ormed using the CP2K package with mixed Gaussian and plane-wave basis set, = using the molecularly optimized MOLOPT double f-valence polarized (mDZVP) b= asis set implemented in CP2K code. Im not asking for a basis set for my stu= dy. I have used B3LYP, CCSD and MP2 function with different basis set to ob= tain an optimization geometry. I ended up with different errors and the str= ucture is broken at the end. I came to know the possibility=C2=A0of freezin= g the coordinates, but at the same time, there is suggestion that the freez= ing is unrealistic and may not be accurate. So in a nutshell, information f= rom anyone who had a similar situation which is resolved would be helpful f= or me.
Thank you for the help


On Wed, Sep 4, = 2019 at 10:09 PM Uche Anene uche=3Duconn.edu <owner-chemistry]*[ccl.net> wrote:
Hi Nikhil,

Choos= ing the correct basis set really depends on you. You are essentially asking= what level of accuracy you willing to accept or is acceptable for your mod= el. That is a question only you can answer. For that, I recommend looking t= hrough literature to see what method and basis set is acceptable for your m= odel/scientific question.

Your are asking question= s that are beyond Gaussian error issues. You should take a step back and re= ad more literature to try to understand what you are doing and what you are= trying to achieve. You may discover that it is acceptable to freeze some o= f the atoms during optimization.

For information o= n basis set, I recommend going through the Gaussian manual:

Happy computing,
Uche


<= div dir=3D"auto" style=3D"text-align:start;text-indent:0px">
---
Uchenna A. Anene
Ph.D. Student,=C2=A0Che= mical Engineering =C2=A0
Uni= versity of Connecticut
Innov= ation Partnership Building=C2=A0
<= span>159 Discovery Drive
Sto= rrs, CT 06269
https://alpay.ims.uconn.edu/uche-anene/#



=

<= /div>




On Sep 4, 2019, at 9:04 AM, Nikhil = Maroli scinikhil*o*gmail.com= <owne= r-chemistry,,ccl.net> wrote:

Thank you very much= for your reply=C2=A0 Mariusz,

Which basis set you to suggest for Cs, Pb and B= r atom. ? (Quantum dot) Sorry, im new to Gaussian or quantum chemistry calc= ulations.

On Wed, Sep 4, 2019 at 6:10 PM Mariusz Radon mariusz.radon%= %gmail.com <owner-chemistry++ccl= .net> wrote:

Sent to CCL by: Mariusz Radon [mariusz.radon.:.gmail.com]

> On 03 Sep 2019, at 16:34, Nikhil Maroli scinikhila/gmail.com <owner-che= mistry _ c= cl.net> wrote:
>
>
> Sent to CCL by: "Nikhil=C2=A0 Maroli" [scinikhil(0)gmail.com]<= br> > Dear all users and experts,
>
> I have modelled cubic structure Cs based quantum dot (perovskite) with=
> correct bond length between Cs-Br and Pb-Br atoms.After few steps of <= br> > optimisation the bond length increases and structure is completely bro= ken.
> I am using Gaussian 09 and started with HF (planned to do B3LYP). can =
> anyone help me to solve the issue.
>

Dear Nikhil:

If you are using an ECP basis set (Pb, Br atoms?), make sure the correct ps= eudopotential has been read correctly. If you accidentally made such an err= or (i.e., starting calculations with an ECP-optimized basis set without act= ually reading in the pseudopotential), Gaussian would not complain, and eve= n (if you are =E2=80=9Clucky=E2=80=9D) you might be able to converge the SC= F - obviously to something very, very unreasonable, so that your geometry w= ill quickly get broken during the optimization.

Best wishes,
Mariusz>
>

--
Mariusz Radon, Ph.D.
Faculty of Chemistry
Jagiellonian University
ul. Ingardena 3
30-060 Krakow, Poland

e-mail: mradon _ chemia.uj.edu.pl
or mariusz.radon _ uj.edu.pl
web: http://www.chemia.uj.edu.pl/~mradon
ORCID:=C2=A0 https://orcid.org/0000-0002-1901-8521



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--
Regards,
Ni= khil Maroli




--
Regards,
Nikhil Maroli

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