From owner-chemistry@ccl.net Thu Mar 15 00:04:00 2012 From: "Seth Olsen seth.olsen*uq.edu.au" To: CCL Subject: CCL: CASSCF does not produce spin densities Message-Id: <-46499-120314235841-5965-neNBpr3GjQ3UURigP32EAw^-^server.ccl.net> X-Original-From: Seth Olsen Content-Type: multipart/alternative; boundary=Apple-Mail-12--858178517 Date: Thu, 15 Mar 2012 13:57:03 +1000 Mime-Version: 1.0 (Apple Message framework v1084) Sent to CCL by: Seth Olsen [seth.olsen{}uq.edu.au] --Apple-Mail-12--858178517 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 On 15/03/2012, at 9:23 AM, J=FCrgen Gr=E4fenstein jurgen-$-chem.gu.se = wrote: >=20 > Sent to CCL by: =3D?iso-8859-1?Q?J=3DFCrgen_Gr=3DE4fenstein?=3D = [jurgen:+:chem.gu.se] >=20 > On 14 Mar, 2012, at 13:48 , Seth Olsen seth.olsen!^!uq.edu.au wrote: >=20 >>=20 >> It's also worth mentioning that I've only ever dealt with = state-averaged problems. It is possible that distinguishing between = "static" and "dynamic" correlations may be operationally useful for = ground state problems, where the idea of a well-defined reference makes = somewhat more sense (although still not very much, because of the = orbital invariance of the CAS expansion). =20 >=20 > The latter is actually no issue. You can rotate the orbitals in a HF = or CASSCF wave function but you will still keep its character, i.e. = single-reference or multi-reference. >=20 Not sure if I understand. The invariant spaces are different for the = two cases. For an evenly-weighted state average, unitaries on the = target space leave the state-averaged ensemble invariant. This latter = point is probably more important than the orbital invariance, because = the idea of a "reference" (i.e. a special state from which the expansion = is built) dissolves; all states in the target space are on the same = footing. I think my point is that the state that is correlated is not = really any state in a state-averaged scheme, but the average ensemble = itself. There are additional complications that arise then, and its = not clear that the concepts used for ground-state models will carry = over. >> It's pretty clear that the consensus is that "static" correlations = are correlations required by the constraint that the state transform as = a particular irrep of the symmetric group, and that that "dynamic" = correlations are associated with the Coulomb hole. >=20 > If there was no Coulomb repulsion the electrons would not avoid each = other and the ground state for H_2, however stretched, would be (1 = \sigma_g)^2. Unfortunately, misleading statements of the kind "dynamic = correlation is driven by Coulomb interaction, static correlation by the = near-degeneracy of two or more configurations" are quite common in the = literature. Both kind of correlations are driven by Coulomb repulsion; = however, a set of quasi-degenerate configurations responds differently = to electron-electron repulsion than a bunch of configurations higher up = in energy. Hmmm. OK. Probably the issue is that the symmetric group constraint = entangles all degrees of freedom while the Coulomb operator generates = pairwise entanglements. Probably the effects aren't separable (which = would be why we are having this discussion, I suppose). This is a = serious problem for mathematics (not just chemistry) because while = pairwise entanglements are amenable to analysis with Schmidt = decompositions (i.e. the SVD), there is no good analogue for tensors of = rank > 2. This problem seems to underlie a lot of current issues. Your point about quasi-deneracy merits some more thought. So, you're = suggesting that when the broadening of the energies by the correlation = is smaller than their splitting, the correlation is "dynamic"? Maybe a = self-energy concept can be leveraged here. >=20 > On the other hand, both static and dynamic correlation has to maintain = the symmetry (more strictly, the IRREP) of the wave function. That is, = in both cases only configurations from the right IRREP contribute to the = CI expansion. Also, dynamic correlation is probably dominated by, but = definitely not restricted to, two.electron interactions. >=20 >> I get all that. But, this tells you right away that it is not = possible to build any operator whose expectation will give you a measure = of pure "static" or "dynamic" correlations. This is because the = requirement of transformation as an irrep of S_n will entangle all = degrees of freedom, while the Coulomb operator generates pairwise = entanglements. The operators act on different Hilbert spaces. -Seth >=20 > The proper definition of static and dynamic correlation becomes = topical in connection with CAS-DFT methods, which a number of authors = (including myself) have struggled and struggle with. In this context, a = physically motivated, "waterproof" definition of the two correlation = contributions would be of great value. I don't envy you having to wrestle with the representability problems = there. =20 >=20 > Best regards, > J=FCrgen >=20 >=20 >=20 > -=3D This is automatically added to each message by the mailing script = =3D- > To recover the email address of the author of the message, please = change>=20>=20>=20 > Subscribe/Unsubscribe:=20>=20>=20 > Job: http://www.ccl.net/jobs=20 > Conferences: = http://server.ccl.net/chemistry/announcements/conferences/ >=20>=20>=20>=20 >=20 --------------------------------------------------- Seth Olsen ARC Australian Research Fellow 6-431 Physics Annexe School of Mathematics and Physics The University of Queensland Brisbane QLD 4072 Australia seth.olsen+/-uq.edu.au +61 7 3365 2816 --------------------------------------------------- Unless stated otherwise, this e-mail represents only the views of the = Sender and not the views of The University of Queensland --Apple-Mail-12--858178517 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1

Sent to CCL by: = =3D?iso-8859-1?Q?J=3DFCrgen_Gr=3DE4fenstein?=3D = [jurgen:+:chem.gu.se]

On 14 Mar, 2012, at 13:48 , Seth Olsen = seth.olsen!^!uq.edu.au wrote:


It's also worth = mentioning that I've only ever dealt with state-averaged problems. =  It is possible that distinguishing between "static" and "dynamic" = correlations may be operationally useful for ground state problems, = where the idea of a well-defined reference makes somewhat more sense = (although still not very much, because of the orbital invariance of the = CAS expansion).  

The latter is actually no = issue. You can rotate the orbitals in a HF or CASSCF wave function but = you will still keep its character, i.e. single-reference or = multi-reference.

Not sure if I = understand.  The invariant spaces are different for the two cases. =  For an evenly-weighted state average, unitaries on the target = space leave the state-averaged ensemble invariant.  This latter = point is probably more important than the orbital invariance, because = the idea of a "reference" (i.e. a special state from which the expansion = is built) dissolves; all states in the target space are on the same = footing.  I think my point is that the state that is correlated is = not really any state in a state-averaged scheme, but the average = ensemble itself.    There are additional complications that = arise then, and its not clear that the concepts used for ground-state = models will carry over.

It's pretty clear that the = consensus is that "static" correlations are correlations required by the = constraint that the state transform as a particular irrep of the = symmetric group, and that that "dynamic" correlations are associated = with the Coulomb hole.

If there was no Coulomb = repulsion the electrons would not avoid each other and the ground state = for H_2, however stretched, would be (1 \sigma_g)^2. Unfortunately, = misleading statements of the kind "dynamic correlation is driven by = Coulomb interaction, static correlation by the near-degeneracy of two or = more configurations" are quite common in the literature. Both kind of = correlations are driven by Coulomb repulsion; however, a set of = quasi-degenerate configurations responds differently to = electron-electron repulsion than a bunch of configurations higher up in = energy.

Hmmm. OK. =  Probably the issue is that the symmetric group constraint = entangles all degrees of freedom while the Coulomb operator generates = pairwise entanglements.  Probably the effects aren't separable = (which would be why we are having this discussion, I suppose). =  This is a serious problem for mathematics (not just chemistry) = because while pairwise entanglements are amenable to analysis with = Schmidt decompositions (i.e. the SVD), there is no good analogue for = tensors of rank > 2.  This problem seems to underlie a lot of = current issues.

Your point about quasi-deneracy = merits some more thought.  So, you're suggesting that when the = broadening of the energies by the correlation is smaller than their = splitting, the correlation is "dynamic"?  Maybe a self-energy = concept can be leveraged here.


On the other hand, both static and dynamic = correlation has to maintain the symmetry (more strictly, the IRREP) of = the wave function. That is, in both cases only configurations from the = right IRREP contribute to the CI expansion. Also, dynamic correlation is = probably dominated by, but definitely not restricted to, two.electron = interactions.

I get all that. =  But, this tells you right away that it is not possible to build = any operator whose expectation will give you a measure of pure "static" = or "dynamic" correlations.  This is because the requirement of = transformation as an irrep of S_n will entangle all degrees of freedom, = while the Coulomb operator generates pairwise entanglements.  The = operators act on different Hilbert spaces. -Seth

The = proper definition of static and dynamic correlation becomes topical in = connection with CAS-DFT methods, which a number of authors (including = myself) have struggled and struggle with. In this context, a physically = motivated, "waterproof" definition of the two correlation contributions = would be of great value.

I = don't envy you having to wrestle with the representability problems = there.  


Best = regards,
J=FCrgen



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+61 7 3365 = 2816
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Unless = stated otherwise, this e-mail represents only the views of the = Sender and not the views of The University of = Queensland

= --Apple-Mail-12--858178517-- From owner-chemistry@ccl.net Thu Mar 15 01:57:01 2012 From: "rv solo rvsolo]|[gmail.com" To: CCL Subject: CCL: How to do ACID analysis? Message-Id: <-46500-120314145248-21983-qcxJvpiPKK+T3Fu2BFThsw**server.ccl.net> X-Original-From: "rv solo" Date: Wed, 14 Mar 2012 14:52:47 -0400 Sent to CCL by: "rv solo" [rvsolo-*-gmail.com] Dear cclrs, i would like to do a anisotropy of the current-induced density (ACID) plot for a organic molecule. Could any one suggest me to use a convenient free program? I am looking forward to hearing from you cclrS. thanking you RV solo From owner-chemistry@ccl.net Thu Mar 15 04:21:00 2012 From: "Georg Lefkidis lefkidis**physik.uni-kl.de" To: CCL Subject: CCL: AW: CASSCF does not produce spin densities Message-Id: <-46501-120315041931-18795-xgckZ2hr9Lhtwmlv9HKTMg|a|server.ccl.net> X-Original-From: "Georg Lefkidis" Content-Language: de Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="iso-8859-1" Date: Thu, 15 Mar 2012 09:19:24 +0100 MIME-Version: 1.0 Sent to CCL by: "Georg Lefkidis" [lefkidis^^physik.uni-kl.de] Dear Jürgen, dear all the problem of defining static vs. dynamical correlations is not an easy one. I have discussed it many times with my physicists colleagues and the consensus (for whatever this is worth) is that dynamic correlations are defined by virtual excitations with well-defined, nonzero energy differences. Following this trail of thoughts the “measure” of the character of the correlations is the energy difference of the Slater determinants in the CI expansion. This is also consistent with the fact that for static correlations one needs multi-reference expansions. This is also connected to the self-energy, in that the static correlations stem from its imaginary part while dynamic mainly originate from its real part. I am not sure I completely understand this, however. My interpretation is that since the static correlations have no energy difference in the denominator of the Green’s function, they can only be imaginary thus leading to broadening, while the energy shifting comes from the real part. In view of this I probably agree with the statement that static correlations mean basically splitting while dynamic basically shifting. What do you think? Best regards Georg >On 15/03/2012, at 9:23 AM, Jürgen Gräfenstein jurgen-$-chem.gu.se wrote: >Your point about quasi-deneracy merits some more thought.  So, you're suggesting that when the broadening of the energies by the correlation is smaller than their splitting, the >correlation is "dynamic"?  Maybe a self-energy concept can be leveraged here. From owner-chemistry@ccl.net Thu Mar 15 05:47:01 2012 From: "cina foroutan canyslopus*_*yahoo.co.uk" To: CCL Subject: CCL: How to do ACID analysis? Message-Id: <-46502-120315051555-15665-g1+awv9xGYHVSQVScouMSA+/-server.ccl.net> X-Original-From: cina foroutan Content-Type: multipart/alternative; boundary="-681287842-811657738-1331802805=:81898" Date: Thu, 15 Mar 2012 09:13:25 +0000 (GMT) MIME-Version: 1.0 Sent to CCL by: cina foroutan [canyslopus_-_yahoo.co.uk] ---681287842-811657738-1331802805=:81898 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Dear RV,=0A=0AI can introduce a quantitative, alternative for ACID, which p= rovides very detailed information about the strengths of the local and glob= al, in-plane and out-of-plane currents in every molecule. You can employ in= tra- and inter-atomic magnetizability data, within the context of the QTAIM= , to gain insight about the patterns of electronic currents in your molecul= e. Intra-atomic magnetizability. These computations can be done by AIMAll s= uite of programs. For details of computations and interpretation of data se= e J. Phys. Chem. A, 2011, 115, 12555.=0AThe out-of-plane interatomic magnet= izability is a quite new index that could be used for assessing magnetic ar= omaticity among various types of molecules. You can also compute contributi= ons of each individual orbital in the total magnetizability/aromaticity of = your molecule quite simply.=0AThis tool is superior to conventional aromati= city indices. Just be careful for comparing the magnetic aromaticity of two= molecules you must be sure that their atoms are of the same type. The othe= r magnetic aromaticity indices, e.g. NICS, ARCS, etc., have the similar pro= blem although no one have ever told it! For details of the factors that aff= ect the magnetic indices see: J. Compute Chem 2011, 32, 2422; Phys. Chem. C= hem. Phys. 2010, 12, 12630; Phys. Chem. Chem. Phys. 2011, 13, 12655 and J. = Phys. Chem. A, 2011, 115, 12708.=0A=0AIf you had any question, do not hesit= ate and directly contact me.=0A=0ACina Foroutan-Nejad, PhD=0ASchool of Chem= istry, University College of Science,=0AUniversity of Tehran, Tehran, Iran.= =0Ahttp://independent.academia.edu/CinaForoutanNejad=0A=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=0A=0A=0A=0A=0A=0A____________= ____________________=0A From: rv solo rvsolo]|[gmail.com =0ATo: "Foroutan-Nejad, Cina " =0AS= ent: Wednesday, 14 March 2012, 22:52=0ASubject: CCL: How to do ACID analysi= s?=0A =0A=0ASent to CCL by: "rv=A0 solo" [rvsolo-*-gmail.com]=0ADear cclrs,= =0A=0A=A0 =A0 =A0 =A0 i would like to do a anisotropy of the current-induc= ed density=A0 (ACID) plot for a organic molecule. Could any one suggest me = to use a convenient free program? I am looking forward to hearing from you = cclrS. =0A=0Athanking you=0A=0ARV solo=0A=0A=0A=0A-=3D This is automaticall= y added to each message by the mailing script =3D-=0ATo recover the email a= ddress of the author of the message, please change=0Athe strange characters= on the top line to the a sign. You can also=0Alook up the X-Original-From:= line in the mail header.=0A=0AE-mail to subscribers: CHEMISTRY a ccl.net or = use:=0A=A0 =A0 =A0=0A=0AE-m= ail to administrators: CHEMISTRY-REQUEST a ccl.net or use=0A=A0 =A0 =A0 http:= //www.ccl.net/cgi-bin/ccl/send_ccl_message=0A=0A=0A= =A0 =A0 =A0=0A=0ABefore postin= g, check wait time at: http://www.ccl.net=0A=0AJob: http://www.ccl.net/jobs= =0A= =0A=0A= =0A=0A=0A=A0 =A0 =A0 ==0A=0ARTFI: http://www.ccl.net/chemistry/abo= utccl/instructions/ ---681287842-811657738-1331802805=:81898 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Dear RV,
=

I can introduce a quantitative, alte= rnative for ACID, which provides very detailed information about the streng= ths of the local and global, in-plane and out-of-plane currents in every mo= lecule. You can employ intra- and inter-atomic magnetizability data, within= the context of the QTAIM, to gain insight about the patterns of electronic= currents in your molecule. Intra-atomic magnetizability. These computation= s can be done by AIMAll suite of programs. For details of computations and = interpretation of data see J. Phys. Chem. A, 2011, 115, 12555.
=
The out-of-plane interatomic magnetizability is a quite new inde= x that could be used for assessing magnetic aromaticity among various types= of molecules. You can also compute contributions of each individual orbital in the total magnetizability/aromaticity of your molecule quite si= mply.
This tool is superior to conventional aromatic= ity indices. Just be careful for comparing the magnetic aromaticity of two = molecules you must be sure that their atoms are of the same type. The other= magnetic aromaticity indices, e.g. NICS, ARCS, etc., have the similar prob= lem although no one have ever told it! For details of the factors that affe= ct the magnetic indices see: J. Compute Chem 2011, 32, 2422; Phys. Chem. Ch= em. Phys. 2010, 12, 12630; Phys. Chem. Chem. Phys. 2011, 13, 12655 and J. P= hys. Chem. A, 2011, 115, 12708.
If you had any q= uestion, do not hesitate and directly contact me.

Cina Foroutan-Nejad, PhD
S= chool of Chemistry, University College of Science,
U= niversity of Tehran, Tehran, Iran.
http://independent.academia.edu/CinaForoutanN= ejad
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D

<= /span>

Fro= m: rv solo rvsolo]|[gmail.com <owner-chemistry a ccl.net> To: "Foroutan-Nejad, Cin= a " <canyslopus a yahoo.co.uk>
Sent: Wednesday, 14 March 2012, 22:52
Subject: CCL: How to do ACID analysis= ?


Sent to CCL by: "rv  solo" [rvsolo-*-gmail.com]
Dear cclrs,

        i = would like to do a anisotropy of the current-induced density  (ACID) p= lot for a organic molecule. Could any one suggest me to use a convenient fr= ee program? I am looking forward to hearing from you cclrS.

thankin= g you

RV solo



-=3D This is automatically added to eac= h message by the mailing script =3D-
To recover the email address of the= author of the message, please change
the strange characters on the top = line to the a sign. You can also
look up the X-Original-From: line in th= e mail header.

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= ---681287842-811657738-1331802805=:81898-- From owner-chemistry@ccl.net Thu Mar 15 08:16:00 2012 From: "Kalaivanan Nagarajan kalaichemis(~)gmail.com" To: CCL Subject: CCL: Electronic circular Dichroism Message-Id: <-46503-120315081539-3116-08sSVsHL+JMUONGyoeTsAA|server.ccl.net> X-Original-From: "Kalaivanan Nagarajan" Date: Thu, 15 Mar 2012 08:15:37 -0400 Sent to CCL by: "Kalaivanan Nagarajan" [kalaichemis^gmail.com] Dear All, I have done the TD-DFT calculation at excited state using 6311-G basis set for my chromophore. After getting UV absorption graph, i saved the data as text file. Then i tried to plot the data in Origin, i always get two graphs, one looks like UV absorption, other one having very poor intensity. Does second one correspond to ECD, or what is that? I am very much confused, can you please clarify this? Thanks in advance. From owner-chemistry@ccl.net Thu Mar 15 09:25:01 2012 From: "Seth Olsen seth.olsen*_*uq.edu.au" To: CCL Subject: CCL: CASSCF does not produce spin densities Message-Id: <-46504-120315003801-20140-643ytHOW4tC3a6kk8RD7ag[-]server.ccl.net> X-Original-From: Seth Olsen Content-Type: multipart/alternative; boundary=Apple-Mail-14--855792323 Date: Thu, 15 Mar 2012 14:36:49 +1000 Mime-Version: 1.0 (Apple Message framework v1084) Sent to CCL by: Seth Olsen [seth.olsen _ uq.edu.au] --Apple-Mail-14--855792323 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 Funny you should mention this, Brian, I'm writing a paper right now that = leverages this idea. There does seem to be a deep connection between = what people call static correlation and the ability to represent the = CASSCF space using chemically meaningful fragment states. This type of = "good" space seems to occur in a way reminiscent of "magic numbers" for = nuclei, etc., in the sense that if you can't factor the orbital space = well into the fragments, then strange behavior emerges (see, e.g. Figure = 4 of J. Phys. Chem. A 2012 vol. 116 (5) pp. 1486-1492. for an = interesting demonstration). -Seth On 15/03/2012, at 4:13 AM, Brian Salter-Duke = brian.james.duke*o*gmail.com wrote: >=20 > Sent to CCL by: Brian Salter-Duke [brian.james.duke]~[gmail.com] > On Wed, Mar 14, 2012 at 09:26:15AM +1000, Seth Olsen = seth.olsen-x-uq.edu.au wrote: >=20 > I agree with my Australian colleage, Seth, but would like to add a > different point. First, it is of course well known that valence bond > theory introduces static correlation. Second, it is also know from the > work of David Cooper and others, that CASSCF functions can be strongly = linked to > spin coupled VB functions. The latter can be projected out of the > CASSCF function and are a very good approximation to the CASSCF. Thus > usefull CASSCF functions are ones that are linked in this way to VB > functions. If we have a larger active space, yes, we are including > dynamic correlation, but perhaps we would be better doing it a = different > way from CASSCF. >=20 > Brian. >=20 >> Sent to CCL by: Seth Olsen [seth.olsen=3D=3D=3Duq.edu.au] >=20 >> With all due respect, I think this conversation is getting foolish. >> The concepts of "static" vs "dynamic" correlation do not have meaning >> in the context of CASSF models. That is, they usually don't have >> well-defined meaning in any case (I.e. everyone has their own) but = any >> reasonable meaning falls apart in a complete active space context - >> because the space is complete! In the asymptotic limit where all >> orbitals are included, it becomes fill CI, and obviously treats both. >> I know of no sensible way to cleanly distinguish the turnover where >> "static" correlation ends and where "dynamic" correlation begins, >> regardless of the length of the expansion. >=20 >> This field needs a revision of its core concepts, soon. Slaughter >> this sacred cow before it rots on its own. >=20 >> Seth Olsen, Ph.D. >> ARC Australian Research Fellow >> School of Mathematics & Physics >> The University of Queensland >> Brisbane, QLD 4072 >> Australia >> +61 7 3365 2816 >>=20 >> On 14/03/2012, at 4:17, "Neese, Frank frank.neese{:}mpi-mail.mpg.de" = wrote: >>=20 >>> In response to Georg and Jim:=20 >>>=20 >>>=20 >>>> with all respect, but Frank Neese's statement is wrong. >>>=20 >>> it looks like we are opening Pandora's box here :-)=20 >>>=20 >>> I nevertheless take the liberty to disagree with the statement = brought forward by Georg. (Not with the stated facts of course. I do = understand what CASSCF is and having programmed diverse multireference = methods over the years I do claim to have at least some appreciation of = multireference wavefunction theory; I know the Schlegl/Robb papers that = were quoted by Georg; they report a convergence enhancement algorithm = for CASSCF wave functions and an application to a reaction between two = very small molecules, i.e. H2CO --> H2 + CO. Very nice work! But IMHO = these papers do not disprove anything I said).=20 >>>=20 >>> My arguments in favor of stating what I have stated in my previous = post are summarized below:=20 >>>=20 >>> As we all know CASSCF is limited to very few number of active = orbitals. The majority of reseachers who have worked intensely in the = field of multiconfigurational self consistent field theory agree that = this type of wavefunction is not meant to cover dynamic correlation = which is what would be required to really go beyond Hartree-Fock level = accuracy. Compared to, say, a closed shell or ROHF CASSCF obviously does = include a tiny amount of dynamic correlation (unless your active space = is trivially small and reduces to the closed shell or ROHF determinant). = However, that tiny little bit of dynamic correlation is essentially = irrelevant. What CASSCF is designed to do is to generalize the = Hartree-Fock method to cases where the single determinant Ansatz is = qualitatively wrong. There are many papers by eminent researchers like = Peter Pulay or Jean Paul Malrieu who state that it would be an abuse of = the CASSCF method to want to cover more than the essential model space = (which is the! > m! >> inimal active space that is needed to cover the static correlation; = that again can mean many things. Sometimes it means ensuring that your = dissociation limit is correctly represented. Obviously here is where = ones chemical thinking comes in). I personally agree with this = reasoning. It is then logical to state that CASSCF is not a high level = method because its accuracy will be similar to that of, say, RHF in the = cases where a closed shell determinant is reasonable. Thus, CASSCF is of = broader applicability (even much broader) and it is more consistent than = R(O)HF, but it is not of strikingly higher accuracy - provided one = compares apples with apples and oranges with oranges. =20 >>>=20 >>> Of course if one defines anything that has more than one determinant = as a post Hartree-Fock method then, yes, there is no doubt that CASSCF = is post-HF. It is not, however, my favorite definition of what a post-HF = method is designed to be. I would tend to use this term if it is implied = that a substantial fraction of the (basis set) dynamic correlation = energy is recovered by the treatment (what is meant by "dynamic = correlation" is, again, a matter of the reference point. If you argue > = > from a multireference perturbation theory or multireference = configuration interaction or multireference coupled cluster point of = view then CASSCF is the starting point and does not contain dynamic = correlation).=20 >>>=20 >>> At the end of the day everybody is of course free to do whatever = calculation one wants and maybe one has good reasons for wanting to = cover some dynamic correlation already with a CASSCF wave function. A = typical example is the double d-shell effect for transition metal = calculations in conjunction with the CASSCF/CASPT2 method that in = particular Kristin Pierloot has elaborated on many times (in this case = one covers a radial correlation effect). My personal preference, = however, is to do this with a post-CASSCF treatment (if one can afford = it).=20 >>>=20 >>> We too have had many good results with CASSCF and transition metals. = My concerns were directed at the particular problem that the colleague = was mentioning. Having worked on both, multireference wavefunctions and = iron nitrosyl systems, I have simply expressed concerns to regard CASSCF = as a high level treatment that should be given preference over any other = theoretical method. To do so would, in my opinion, require solid backup = > from comparison of calculated to observed physical properties.=20 >>>=20 >>> The discussion that we have been starting here could very quickly = turn into a hair splitting dispute about terminology and I hope that = this is not what will happen. I have simply tried here to explain what = my take on the subject is and I do, of course, respect any other = approach or opinion that leads to creative and interesting science.=20 >>>=20 >>> Best regards >>> Frank >>>=20 >>> = ------------------------------------------------------------------------- >>> Prof. Dr. Frank Neese >>> - Director - >>> Max-Planck Institut f=FCr Bioanorganische Chemie >>> Stiftstr. 34-36 >>> D-45470 M=FClheim an der Ruhr >>> Germany >>> E-Mail: Frank.Neese]~[mpi-mail.mpg.de >>> = ------------------------------------------------------------------------->= =20 >=20 > --=20 > Brian Salter-Duke (Brian Duke) Brian.Salter-Duke{=3D}monash.edu > Adjunct Associate Professor > Monash Institute of Pharmaceutical Sciences > Monash University Parkville Campus, VIC 3052, Australia >=20 >=20 >=20 > -=3D This is automatically added to each message by the mailing script = =3D- > To recover the email address of the author of the message, please = change>=20>=20>=20 > Subscribe/Unsubscribe:=20>=20>=20 > Job: http://www.ccl.net/jobs=20 > Conferences: = http://server.ccl.net/chemistry/announcements/conferences/ >=20>=20>=20>=20 >=20 --------------------------------------------------- Seth Olsen ARC Australian Research Fellow 6-431 Physics Annexe School of Mathematics and Physics The University of Queensland Brisbane QLD 4072 Australia seth.olsen^_^uq.edu.au +61 7 3365 2816 --------------------------------------------------- Unless stated otherwise, this e-mail represents only the views of the = Sender and not the views of The University of Queensland --Apple-Mail-14--855792323 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 Funny = you should mention this, Brian, I'm writing a paper right now that = leverages this idea.  There does seem to be a deep connection = between what people call static correlation and the ability to represent = the CASSCF space using chemically meaningful fragment states.  This = type of "good" space seems to occur in a way reminiscent of "magic = numbers" for nuclei, etc., in the sense that if you can't factor the = orbital space well into the fragments, then strange behavior emerges = (see, e.g. Figure 4 of J. Phys. Chem. A 2012 vol. 116 (5) pp. = 1486-1492. for an interesting demonstration). =  -Seth



On = 15/03/2012, at 4:13 AM, Brian Salter-Duke brian.james.duke*o*gmail.com = wrote:


Sent to CCL by: Brian Salter-Duke = [brian.james.duke]~[gmail.com]
On Wed, Mar 14, 2012 at 09:26:15AM = +1000, Seth Olsen seth.olsen-x-uq.edu.au = wrote:

I agree with my Australian colleage, Seth, but would like = to add a
different point. First, it is of course well known that = valence bond
theory introduces static correlation. Second, it is also = know from the
work of David Cooper and others, that CASSCF functions = can be strongly linked to
spin coupled VB functions. The latter can = be projected out of the
CASSCF function and are a very good = approximation to the CASSCF. Thus
usefull CASSCF functions are ones = that are linked in this way to VB
functions. If we have a larger = active space, yes, we are including
dynamic correlation, but perhaps = we would be better doing it a different
way from = CASSCF.

Brian.

Sent to CCL by: = Seth Olsen [seth.olsen=3D=3D=3Duq.edu.au]

With all due respect, I think this conversation is getting = foolish.
The concepts of = "static" vs "dynamic" correlation do not have = meaning
in the context of = CASSF models.  That is, they usually don't = have
well-defined meaning in = any case (I.e. everyone has their own) but = any
reasonable meaning falls = apart in a complete active space context -
because the space is complete!  In the asymptotic = limit where all
orbitals are = included, it becomes fill CI, and obviously treats = both.
I know of no sensible = way to cleanly distinguish the turnover = where
"static" correlation = ends and where "dynamic" correlation begins,
regardless of the length of the = expansion.

This field = needs a revision of its core concepts, soon. =  Slaughter
this sacred = cow before it rots on its own.

Seth Olsen, Ph.D.
ARC Australian Research Fellow
School of Mathematics & = Physics
The University of = Queensland
Brisbane, QLD = 4072
Australia
+61 7 = 3365 2816

On 14/03/2012, = at 4:17, "Neese, Frank frank.neese{:}mpi-mail.mpg.de" = <owner-chemistry..ccl.net> wrote:

In response to Georg and Jim: =


with = all respect, but Frank Neese's statement is = wrong.

it looks like we are opening = Pandora's box here :-)

I nevertheless take the liberty = to disagree with the statement brought forward by Georg. (Not with the = stated facts of course. I do understand what CASSCF is and having = programmed diverse multireference methods over the years I do claim to = have at least some  appreciation of multireference wavefunction = theory; I know the Schlegl/Robb papers that were quoted by Georg; they = report a convergence enhancement algorithm for CASSCF wave functions and = an application to a reaction between two very small molecules, i.e. =  H2CO --> H2 + CO. Very nice work! But IMHO these papers do not = disprove anything I said).

My arguments in favor of stating = what I have stated in my previous post are summarized below: =

As we all know CASSCF is limited = to very few number of active orbitals. The majority of reseachers who = have worked intensely in the field of multiconfigurational self = consistent field theory agree that this type of wavefunction is not = meant to cover dynamic correlation which is what would be required to = really go beyond Hartree-Fock level accuracy. Compared to, say, a closed = shell or ROHF CASSCF obviously does include a tiny amount of dynamic = correlation (unless your active space is trivially small and reduces to = the closed shell or ROHF determinant). However, that tiny little bit of = dynamic correlation is essentially irrelevant. What CASSCF is designed = to  do is to generalize the Hartree-Fock method to cases where the = single determinant Ansatz is qualitatively wrong. There are many papers = by eminent researchers like Peter Pulay or Jean Paul Malrieu who state = that it would be an abuse of the CASSCF method to want to cover more = than the essential model space (which is = the!
 m!
= inimal active space that is needed to cover the static correlation; that = again can mean many things. Sometimes it means ensuring that your = dissociation limit is correctly represented. Obviously here is where = ones chemical thinking comes in). I personally  agree with this = reasoning. It is then logical to state that CASSCF is not a high level = method because its accuracy will be similar to that of, say, RHF in the = cases where a closed shell determinant is reasonable. Thus, CASSCF is of = broader applicability (even much broader) and it is more consistent than = R(O)HF, but it is not of strikingly higher accuracy - provided one = compares apples with apples and oranges with oranges. =  

Of course if one defines = anything that has more than one determinant as a post Hartree-Fock = method then, yes, there is no doubt that CASSCF is post-HF. It is not, = however, my favorite definition of what a post-HF method is designed to = be. I would tend to use this term if it is implied that a substantial = fraction of the (basis set) dynamic correlation energy is recovered by = the treatment (what is meant by "dynamic correlation" is, again, a = matter of the reference point. If you argue > from a multireference = perturbation theory or multireference configuration interaction or = multireference coupled cluster point of view then CASSCF is the starting = point and does not contain dynamic correlation). =

At the end of the day everybody = is of course free to do whatever calculation one wants and maybe one has = good reasons for wanting to cover some dynamic correlation already with = a CASSCF wave function. A typical example is the double d-shell effect = for transition metal calculations in conjunction with the CASSCF/CASPT2 = method that in particular Kristin Pierloot has elaborated on many times = (in this case one covers a radial correlation effect). My personal = preference, however, is to do this with a post-CASSCF treatment (if one = can afford it).

We too have had many good = results with CASSCF and transition metals. My concerns were directed at = the particular problem that the colleague was mentioning. Having worked = on both, multireference wavefunctions and iron nitrosyl systems, I have = simply expressed concerns to regard CASSCF as a high level treatment = that should be given preference over any other theoretical method. To do = so would, in my opinion, require solid backup > from comparison of = calculated to observed physical properties. =

The discussion that we have been = starting here could very quickly turn into a hair splitting dispute = about terminology and I hope that this is not what will happen. I have = simply tried here to explain what my take  on the subject is and I = do, of course, respect any other approach or opinion that leads to = creative and interesting science. =

Best = regards
Frank

------------------------------------------------------------= -------------
Prof. Dr. Frank = Neese
- Director -
Max-Planck Institut f=FCr = Bioanorganische Chemie
Stiftstr. = 34-36
D-45470 M=FClheim an der = Ruhr
Germany
E-Mail: = Frank.Neese]~[mpi-mail.mpg.de
------------------------------------------------------------= ------------->

--
=   Brian Salter-Duke (Brian Duke) =   Brian.Salter-Duke{=3D}monash.edu
=             &n= bsp;      Adjunct Associate Professor
=            Monash = Institute of Pharmaceutical Sciences
=      Monash University Parkville Campus, VIC = 3052, Australia



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<= /div>
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+61 7 3365 = 2816
---------------------------------------------------
Unless = stated otherwise, this e-mail represents only the views of the = Sender and not the views of The University of = Queensland

= --Apple-Mail-14--855792323-- From owner-chemistry@ccl.net Thu Mar 15 10:00:00 2012 From: "Rinderspacher, Berend C CIV (US) berend.c.rinderspacher.civ[*]mail.mil" To: CCL Subject: CCL: AW: CASSCF does not produce spin densities (UNCLASSIFIED) Message-Id: <-46505-120315075851-28968-uzlduPO5zokyq9rb93Gyew{}server.ccl.net> X-Original-From: "Rinderspacher, Berend C CIV (US)" Content-Language: en-US Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="iso-8859-1" Date: Thu, 15 Mar 2012 11:58:44 +0000 MIME-Version: 1.0 Sent to CCL by: "Rinderspacher, Berend C CIV (US)" [berend.c.rinderspacher.civ!A!mail.mil] Classification: UNCLASSIFIED Caveats: NONE Why not define dynamic correlation as the contribution to the energy from the second order cumulant (D^(2)-1/N D^(1)\wedge D^(1))? Since the correlation energy is already defined as the difference to the HF energy, or more generally, \min_{Slaters \phi} <\Psi|\phi><\phi|H|\phi><\phi|\Psi>, whatever is left over is static correlation. At least that's how I think about it. Christopher -----Original Message----- > From: owner-chemistry+berend.rinderspacher==us.army.mil*o*ccl.net [mailto:owner-chemistry+berend.rinderspacher==us.army.mil*o*ccl.net] On Behalf Of Georg Lefkidis lefkidis**physik.uni-kl.de Sent: Thursday, March 15, 2012 4:19 AM To: Rinderspacher, Berend C CIV (US) Subject: CCL: AW: CASSCF does not produce spin densities Sent to CCL by: "Georg Lefkidis" [lefkidis^^physik.uni-kl.de] Dear Jürgen, dear all the problem of defining static vs. dynamical correlations is not an easy one. I have discussed it many times with my physicists colleagues and the consensus (for whatever this is worth) is that dynamic correlations are defined by virtual excitations with well-defined, nonzero energy differences. Following this trail of thoughts the "measure" of the character of the correlations is the energy difference of the Slater determinants in the CI expansion. This is also consistent with the fact that for static correlations one needs multi-reference expansions. This is also connected to the self-energy, in that the static correlations stem from its imaginary part while dynamic mainly originate from its real part. I am not sure I completely understand this, however. My interpretation is that since the static correlations have no energy difference in the denominator of the Green's function, they can only be imaginary thus leading to broadening, while the energy shifting comes from the real part. In view of this I probably agree with the statement that static correlations mean basically splitting while dynamic basically shifting. What do you think? Best regards Georg >On 15/03/2012, at 9:23 AM, Jürgen Gräfenstein jurgen-$-chem.gu.se wrote: >Your point about quasi-deneracy merits some more thought.  So, you're suggesting that when the broadening of the energies by the correlation is smaller than their splitting, the >correlation is "dynamic"?  Maybe a self-energy concept can be leveraged here.http://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txtClassification: UNCLASSIFIED Caveats: NONE From owner-chemistry@ccl.net Thu Mar 15 12:57:00 2012 From: "Avik Sanyal avik.sanyal..aci.uni-heidelberg.de" To: CCL Subject: CCL: Partial charges from Quantum Chemistry Message-Id: <-46506-120315125432-3871-iYM6M3jSg3Kpik6ydboLbQ##server.ccl.net> X-Original-From: "Avik Sanyal" Date: Thu, 15 Mar 2012 12:54:30 -0400 Sent to CCL by: "Avik Sanyal" [avik.sanyal_+_aci.uni-heidelberg.de] Dear CCL-ers, I am interested in computing partial atomic charges for transition metal systems (viz, ions of Fe, Mn, Co and Cu surrounded by amine-based ligands). But I find in literature that there are a large number of QC charge schemes that one can use - Mulliken, NPA, QTAIM, Hirshfeld, ESP-based charges etc. I have made some calculations with these schemes and the results vary a great deal from one method to another. My question is: which method works well for transition metal complexes? Has there been a publication/review comparing the performances of the various methods? Many thanks in advance. Avik Sanyal From owner-chemistry@ccl.net Thu Mar 15 13:31:01 2012 From: "Dr. Vitaly V. Chaban vvchaban _ gmail.com" To: CCL Subject: CCL: Partial charges from Quantum Chemistry Message-Id: <-46507-120315132907-26473-3FvgNqjGV8kYCqwSpvU7Tg!A!server.ccl.net> X-Original-From: "Dr. Vitaly V. Chaban" Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=ISO-8859-1 Date: Thu, 15 Mar 2012 13:28:19 -0400 MIME-Version: 1.0 Sent to CCL by: "Dr. Vitaly V. Chaban" [vvchaban ~ gmail.com] It is better to ask which charges are good for which purposes. Mulliken is good to qualitatively compare electron distribution within a molecules. ESP-based charges are good to construct MM models. Hirshelfd charges are good to extimate charge transfer between e.g. two molecules. -- Dr. Vitaly V. Chaban, 430 Hutchison Hall, Chem. Dept. Univ. Rochester, Rochester, New York 14627-0216 THE UNITED STATES OF AMERICA On Thu, Mar 15, 2012 at 12:54 PM, Avik Sanyal avik.sanyal..aci.uni-heidelberg.de wrote: > > Sent to CCL by: "Avik  Sanyal" [avik.sanyal_+_aci.uni-heidelberg.de] > Dear CCL-ers, > > I am interested in computing partial atomic charges for transition metal systems (viz, ions of Fe, Mn, Co and Cu surrounded by amine-based ligands). But I find in literature that there are a large number of QC charge schemes that one can use - Mulliken, NPA, QTAIM, Hirshfeld, ESP-based charges etc. I have made some calculations with these schemes and the results vary a great deal from one method to another. > > My question is: which method works well for transition metal complexes? Has there been a publication/review comparing the performances of the various methods? > > Many thanks in advance. > > Avik Sanyal>      http://www.ccl.net/cgi-bin/ccl/send_ccl_message>      http://www.ccl.net/cgi-bin/ccl/send_ccl_message>      http://www.ccl.net/chemistry/sub_unsub.shtml>      http://www.ccl.net/spammers.txt> > From owner-chemistry@ccl.net Thu Mar 15 14:07:01 2012 From: "Dr. Vitaly V. Chaban vvchaban _ gmail.com" To: CCL Subject: CCL:G: PBC calculations Message-Id: <-46508-120314150334-19048-W30/KHsYu3Lb8/rvJed+Ng * server.ccl.net> X-Original-From: "Dr. Vitaly V. Chaban" Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=ISO-8859-1 Date: Wed, 14 Mar 2012 15:02:45 -0400 MIME-Version: 1.0 Sent to CCL by: "Dr. Vitaly V. Chaban" [vvchaban~~gmail.com] Do you use any k-mesh? Dr. Vitaly V. Chaban, 430 Hutchison Hall, Chem. Dept. Univ. Rochester, Rochester, New York 14627-0216 THE UNITED STATES OF AMERICA On Wed, Mar 14, 2012 at 5:06 AM, Anja Jatsch pipek..gmx.net wrote: > > Sent to CCL by: "Anja  Jatsch" [pipek:+:gmx.net] > Dear ccl users, > > I am trying to set up a PBC calculation on a measured crystal structure (organic), but I always end up with the same error in the MO guess: > > Dimensions of /B2/ exceeded in AtP2B2. > Error termination via Lnk1e in c:\program files\G09W\l401.exe > > I am using #p pbepbe/3-21g/auto and I really dont have a clue whats the problem. There are almost 200 atoms in the unit cell, maybe its to large? But Gaussian doesnt complain about the memory > > Thanks a lot for any idears! > > Anja>      http://www.ccl.net/cgi-bin/ccl/send_ccl_message>      http://www.ccl.net/cgi-bin/ccl/send_ccl_message>      http://www.ccl.net/chemistry/sub_unsub.shtml>      http://www.ccl.net/spammers.txt> > From owner-chemistry@ccl.net Thu Mar 15 14:42:01 2012 From: "Nuno A. G. Bandeira nuno.bandeira*ist.utl.pt" To: CCL Subject: CCL: Partial charges from Quantum Chemistry Message-Id: <-46509-120315143245-7997-Tixf4Kam84fPqpXBXzr6kg#server.ccl.net> X-Original-From: "Nuno A. G. Bandeira" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Date: Thu, 15 Mar 2012 18:32:37 +0000 MIME-Version: 1.0 Sent to CCL by: "Nuno A. G. Bandeira" [nuno.bandeira,+,ist.utl.pt] On 15-03-2012 16:54, Avik Sanyal avik.sanyal..aci.uni-heidelberg.de wrote: > Sent to CCL by: "Avik Sanyal" [avik.sanyal_+_aci.uni-heidelberg.de] > Dear CCL-ers, > > I am interested in computing partial atomic charges for transition metal systems (viz, ions of Fe, Mn, Co and Cu surrounded by amine-based ligands). But I find in literature that there are a large number of QC charge schemes that one can use - Mulliken, NPA, QTAIM, Hirshfeld, ESP-based charges etc. I have made some calculations with these schemes and the results vary a great deal from one method to another. > > My question is: which method works well for transition metal complexes? Has there been a publication/review comparing the performances of the various methods? > Yes. Try this one: Fonseca Guerra, C.; Handgraaf, J.-W.; Baerends, E. J.; Bickelhaupt, F. M. Voronoi deformation density (VDD) charges: Assessment of the Mulliken, Bader, Hirshfeld, Weinhold, and VDD methods for charge analysis J. Comput. Chem. 2004, 25, 189-210 -- Nuno A. G. Bandeira, AMRSC -- From owner-chemistry@ccl.net Thu Mar 15 22:07:00 2012 From: "Daniele Gianni daniele.gianni###gmail.com" To: CCL Subject: CCL: ***Extended deadline: March 26*** COMETS 2012 - 3rd International Track on Collaborative Modeling and Simulation - Call for Papers Message-Id: <-46510-120315183424-25207-yG5DdpoVdA8JFolNT99mUw*server.ccl.net> X-Original-From: Daniele Gianni Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=windows-1252 Date: Thu, 15 Mar 2012 23:34:15 +0100 MIME-Version: 1.0 Sent to CCL by: Daniele Gianni [daniele.gianni!=!gmail.com] ************* Deadline Extended to March 26, 2012 *************** (Please accept our apologies if you receive multiple copies of this message) #################################################################                       IEEE WETICE 2012     3rd IEEE Track on Collaborative Modeling and Simulation                         (Comets 2012)                       in cooperation with                   AFIS (INCOSE France Chapter)               MIMOS (Italian Association for M&S)                       CALL FOR PAPERS ################################################################# June 25-27, 2012, Toulouse (France) http://www.sel.uniroma2.it/comets12 ################################################################# # Papers Due: March 26, 2012 **** Extended Deadline **** # Accepted papers will be published in the conference proceedings # by the IEEE Computer Society Press and indexed by EI. ################################################################# Modeling and Simulation (M&S) is increasingly becoming a central activity in the design of new systems and in the analysis of existing systems because it enables designers and researchers to investigate systems behavior through virtual representations. For this reason, M&S is gaining a primary role in many industrial and research fields, such as space, critical infrastructures, manufacturing, emergency management, biomedical systems and sustainable future. However, as the complexity of the investigated systems increases and the types of investigations widens, the cost of M&S activities increases for the more complex models and for the communications among a wider number and variety of M&S stakeholders (e.g., sub-domain experts, simulator users, simulator engineers, and final system users). To address the increasing costs of M&S activities, collaborative technologies must be introduced to support these activities by fostering the sharing and reuse of models, by facilitating the communications among M&S stakeholders, and more generally by integrating processes, tools and platforms. Aside from seeking applications of collaborative technologies to M&S activities, the track seeks innovative contributions that deal with the application of M&S practices to the design of collaborative environments. These environments are continuously becoming more complex, and therefore their design requires systematic approaches to meet the required quality of collaboration. This is important for two reasons: to reduce rework activities on the actual collaborative environment, and to maximize the productivity and the quality of the process the collaborative environment supports. M&S offers the methodologies and tools for such investigations and therefore it can be used to improve the quality of collaborative environments. A non–exhaustive list of topics of interest includes: * collaborative environments for M&S * collaborative Systems of Systems M&S * workflow modelling for collaborative environments and processes * agent-based M&S * collaborative distributed simulation * collaborative component-based M&S * net-centric M&S * web-based M&S * model sharing and reuse * model building and evaluation * modeling and simulation of business processes * modeling for collaboration * simulation-based performance evaluation of collaborative networks * model-driven simulation engineering * domain specific languages for the simulation of collaborative environments * domain specific languages for collaborative M&S * databases and repositories for M&S * distributed virtual environments * virtual research environment for M&S * collaborative DEVS M&S To stimulate creativity, however, the track maintains a wider scope and invites interested researchers to present contributions that offer original perspectives on collaboration and M&S. +++++++++++++++++++++++++++++++++++ On-Line Submissions and Publication +++++++++++++++++++++++++++++++++++ CoMetS'12 intends to bring together researchers and practitioners to discuss key issues, approaches, open problems, innovative applications and trends in the track research area. This year, we will accept submissions in two forms: (1) papers (2) poster and industrial presentations (1) Papers should contain original contributions not published or submitted elsewhere. Papers up to six pages (including figures, tables and references) can be submitted. Papers should follow the IEEE format, which is single spaced, two columns, 10 pt Times/Roman font. All submissions should be electronic (in PDF) and will be peer-reviewed by at least three program committee members. Accepted full papers will be included in the proceedings and published by the IEEE Computer Society Press (IEEE approval pending). Please note that at least one author for each accepted paper should register to attend WETICE 2012 (http://www.wetice.org) to have the paper published in the proceedings. (2) Posters should describe a practical, on-the-field, experience in any domain area using collaborative M&S. The poster submission requires the submission of an abstract for evaluation from the organizers. Accepted abstract must be followed by the submission of a poster which will be displayed at conference time. With the poster submission, a short (15 minutes) slot might be allocated for oral presentation illustrating the industrial case. The presentation may also include a live demo, but it should not include commercial details. Interested authors and participants may contact the organizers for expression of interests and content appropriateness at any time. Papers and posters can be submitted in PDF format at the submission site (https://www.easychair.org/conferences/?conf=comets2012), which is supported by the EasyChair conference management system. Please feel free to contact the track chairs (comets2012(a)easychair.org) if you experience problems with the EasyChair Web site. +++++++++++++++ Important Dates +++++++++++++++ * Submission Deadline: March 26, 2012 **** Extended deadline **** * Notification to authors: April 16, 2012 * Camera Ready to IEEE: April 30, 2012 * Conference dates: June 25 - June 27, 2012 ++++++++++++++++++++ Organizing Committee ++++++++++++++++++++ * Andrea D'Ambrogio, University of Roma TorVergata, Italy * Daniele Gianni, European Space Agency, The Netherlands * Joachim Fuchs, European Space Agency, The Netherlands * Giuseppe Iazeolla, University of Roma TorVergata, Italy +++++++++++++++++ Program Committee +++++++++++++++++ * Santiago Balestrini, Georgia Institute of Technology, USA * Massimo Bandecchi, European Space Agency, The Netherlands * Joseph Giampapa, SEI, Carnegie Mellon University, USA * Alain Kerbrat, CollESys - AFIS, France * Axel Lehmann, Universitaet der Bundeswehr Muenchen, Germany * Cristiano Leorato, Rhea, The Netherlands * Steve McKeever, University of Oxford, UK * David Nickerson, Auckland Bioengineering Institute, NZ * Alfred Park, Oak Ridge National Laboratory, USA * Wolfgang Prinz, Fraunhofer FIT and RWTH Aachen, Germany * José L. Risco-Martin, Universidad Complutense de Madrid, Spain * Jean-Francois Santucci, University of Corsica, France * Gabriel Wainer, Carleton University, Canada * Quirien Wijnand, European Space Agency, The Netherlands * Justyna Zander, Harvard University, USA, and Fraunhofer Institute FOKUS, Germany * Heming Zhang, Tsinghua University, China *** Contact Information *** Daniele Gianni (track co-chair) Email: danielegmail-comets(a)yahoo.it COMETS 2012 - 3rd IEEE Track on Collaborative Modeling and Simulation - Call for Papers ************* Deadline Extended to March 26, 2012 *************** (Please accept our apologies if you receive multiple copies of this message) #################################################################                       IEEE WETICE 2012     3rd IEEE Track on Collaborative Modeling and Simulation                         (Comets 2012)                       in cooperation with                   AFIS (INCOSE France Chapter)               MIMOS (Italian Association for M&S)                       CALL FOR PAPERS ################################################################# June 25-27, 2012, Toulouse (France) http://www.sel.uniroma2.it/comets12 ################################################################# # Papers Due: March 26, 2012 **** Extended Deadline **** # Accepted papers will be published in the conference proceedings # by the IEEE Computer Society Press and indexed by EI. ################################################################# Modeling and Simulation (M&S) is increasingly becoming a central activity in the design of new systems and in the analysis of existing systems because it enables designers and researchers to investigate systems behavior through virtual representations. For this reason, M&S is gaining a primary role in many industrial and research fields, such as space, critical infrastructures, manufacturing, emergency management, biomedical systems and sustainable future. However, as the complexity of the investigated systems increases and the types of investigations widens, the cost of M&S activities increases for the more complex models and for the communications among a wider number and variety of M&S stakeholders (e.g., sub-domain experts, simulator users, simulator engineers, and final system users). To address the increasing costs of M&S activities, collaborative technologies must be introduced to support these activities by fostering the sharing and reuse of models, by facilitating the communications among M&S stakeholders, and more generally by integrating processes, tools and platforms. Aside from seeking applications of collaborative technologies to M&S activities, the track seeks innovative contributions that deal with the application of M&S practices to the design of collaborative environments. These environments are continuously becoming more complex, and therefore their design requires systematic approaches to meet the required quality of collaboration. This is important for two reasons: to reduce rework activities on the actual collaborative environment, and to maximize the productivity and the quality of the process the collaborative environment supports. M&S offers the methodologies and tools for such investigations and therefore it can be used to improve the quality of collaborative environments. A non–exhaustive list of topics of interest includes: * collaborative environments for M&S * collaborative Systems of Systems M&S * workflow modelling for collaborative environments and processes * agent-based M&S * collaborative distributed simulation * collaborative component-based M&S * net-centric M&S * web-based M&S * model sharing and reuse * model building and evaluation * modeling and simulation of business processes * modeling for collaboration * simulation-based performance evaluation of collaborative networks * model-driven simulation engineering * domain specific languages for the simulation of collaborative environments * domain specific languages for collaborative M&S * databases and repositories for M&S * distributed virtual environments * virtual research environment for M&S * collaborative DEVS M&S To stimulate creativity, however, the track maintains a wider scope and invites interested researchers to present contributions that offer original perspectives on collaboration and M&S. +++++++++++++++++++++++++++++++++++ On-Line Submissions and Publication +++++++++++++++++++++++++++++++++++ CoMetS'12 intends to bring together researchers and practitioners to discuss key issues, approaches, open problems, innovative applications and trends in the track research area. This year, we will accept submissions in two forms: (1) papers (2) poster and industrial presentations (1) Papers should contain original contributions not published or submitted elsewhere. Papers up to six pages (including figures, tables and references) can be submitted. Papers should follow the IEEE format, which is single spaced, two columns, 10 pt Times/Roman font. All submissions should be electronic (in PDF) and will be peer-reviewed by at least three program committee members. Accepted full papers will be included in the proceedings and published by the IEEE Computer Society Press (IEEE approval pending). Please note that at least one author for each accepted paper should register to attend WETICE 2012 (http://www.wetice.org) to have the paper published in the proceedings. (2) Posters should describe a practical, on-the-field, experience in any domain area using collaborative M&S. The poster submission requires the submission of an abstract for evaluation from the organizers. Accepted abstract must be followed by the submission of a poster which will be displayed at conference time. With the poster submission, a short (15 minutes) slot might be allocated for oral presentation illustrating the industrial case. The presentation may also include a live demo, but it should not include commercial details. Interested authors and participants may contact the organizers for expression of interests and content appropriateness at any time. Papers and posters can be submitted in PDF format at the submission site (https://www.easychair.org/conferences/?conf=comets2012), which is supported by the EasyChair conference management system. Please feel free to contact the track chairs (comets2012(a)easychair.org) if you experience problems with the EasyChair Web site. +++++++++++++++ Important Dates +++++++++++++++ * Submission Deadline: March 26, 2012 **** Extended deadline **** * Notification to authors: April 16, 2012 * Camera Ready to IEEE: April 30, 2012 * Conference dates: June 25 - June 27, 2012 ++++++++++++++++++++ Organizing Committee ++++++++++++++++++++ * Andrea D'Ambrogio, University of Roma TorVergata, Italy * Daniele Gianni, European Space Agency, The Netherlands * Joachim Fuchs, European Space Agency, The Netherlands * Giuseppe Iazeolla, University of Roma TorVergata, Italy +++++++++++++++++ Program Committee +++++++++++++++++ * Santiago Balestrini, Georgia Institute of Technology, USA * Massimo Bandecchi, European Space Agency, The Netherlands * Joseph Giampapa, SEI, Carnegie Mellon University, USA * Alain Kerbrat, CollESys - AFIS, France * Axel Lehmann, Universitaet der Bundeswehr Muenchen, Germany * Cristiano Leorato, Rhea, The Netherlands * Steve McKeever, University of Oxford, UK * David Nickerson, Auckland Bioengineering Institute, NZ * Alfred Park, Oak Ridge National Laboratory, USA * Wolfgang Prinz, Fraunhofer FIT and RWTH Aachen, Germany * José L. Risco-Martin, Universidad Complutense de Madrid, Spain * Jean-Francois Santucci, University of Corsica, France * Gabriel Wainer, Carleton University, Canada * Quirien Wijnand, European Space Agency, The Netherlands * Justyna Zander, Harvard University, USA, and Fraunhofer Institute FOKUS, Germany * Heming Zhang, Tsinghua University, China *** Contact Information *** Daniele Gianni (track co-chair) Email: danielegmail-comets(a)yahoo.it