Dear Dr. Hesselmann,<br><br> Many thanks your reply. I was considering \delta HF term from HF-SAPT with frozen core. <span dir="ltr"></span>I thought density fitting (which can affect freeze core) is only for non-hybrid DFT. Actually as mentioned in the manual, it is already implemented for HF at level 1 and 2, which is sufficient for \delta HF calculation. Now everything is clear.<br>
<br>Thanks once more for your help<br>Best regards<br>Cong Wang<br><br>Ph. D. Student<br>Department of Chemistry
<br>Laboratory for Instruction in Swedish
<br>University of Helsinki
<br>A.I. Virtanens plats 1
<br>P.O. Box 55
<br>FI-00014 University of Helsinki
<br>FINLAND
<br><br><div class="gmail_quote">On Mon, Feb 22, 2010 at 5:40 PM, Andreas Hesselmann <span dir="ltr"><<a href="mailto:andreas.hesselmann@chemie.uni-erlangen.de" target="_blank">andreas.hesselmann@chemie.uni-erlangen.de</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Dear Cong,<br>
<br>
yes, the core orbitals are usually defined as the<br>
orbitals with the lowest orbital energies.<br>
<br>
I am a bit uncertain about your 2nd question. If you<br>
are interested in accurate interaction energies you<br>
shouldn't use either HF or LHF for the monomer calculations<br>
as you wouln't account for intramonomer correlation effects.<br>
As described in the manual, it will be much better<br>
to use density functionals in combination with an<br>
asymptotic correction for the xc-potential (see manual).<br>
<br>
Best wishes,<br>
<font color="#888888">Andreas<br>
</font><div><div></div><div><br>
<br>
<br>
<br>
<br>
<br>
On Monday 22 February 2010 13:32, you wrote:<br>
> Dear Dr. Hesselmann,<br>
><br>
> Many thanks for your help!<br>
><br>
> Excuse me, what does "excluding the valence orbitals" mean? (will the<br>
> frozen orbital automatically be chosen from low to high orbital energy?)<br>
> Also, as you mentioned, the frozen core only affects the density-fitting<br>
> calculation, does it imply if I use Hartree-Fock monomer, it is impossible<br>
> to freeze any orbital unless circumvent the problem by lhf. If so, is there<br>
> any comparison available about the accuracy HF-SAPT vs LHF-SAPT for some<br>
> given set of molecules?<br>
><br>
> Thank you very much<br>
> Best regards<br>
> Cong Wang<br>
> Ph. D. Student<br>
><br>
> Department of Chemistry<br>
> Laboratory for Instruction in Swedish<br>
> University of Helsinki<br>
> A.I. Virtanens plats 1<br>
> P.O. Box 55<br>
> FI-00014 University of Helsinki<br>
> FINLAND<br>
><br>
><br>
><br>
> On Mon, Feb 22, 2010 at 12:44 PM, Andreas Hesselmann <<br>
><br>
> <a href="mailto:andreas.hesselmann@chemie.uni-erlangen.de" target="_blank">andreas.hesselmann@chemie.uni-erlangen.de</a>> wrote:<br>
> > Dear Cong,<br>
> ><br>
> > The number to be specified in the frozena/b<br>
> > option is the number of occupied orbitals<br>
> > excluding the valence orbitals.<br>
> ><br>
> > The frozen core option will only effect the 2nd<br>
> > order terms in the density-fitting part of the<br>
> > SAPT program (and indunction only if SAPT_ICPKS=0).<br>
> > For the 1st order terms it is important to include<br>
> > all occupied orbitals, otherwise the interaction energy<br>
> > will not be very accurate for small distances of the<br>
> > monomers.<br>
> ><br>
> > Best wishes,<br>
> > Andreas<br>
> ><br>
> > On Saturday 20 February 2010 17:46, cong.wang wrote:<br>
> > > Dear everyone,<br>
> > ><br>
> > > Hello,<br>
> > ><br>
> > > Excuse me, I have two questions about the frozen core in the SAPT<br>
> > > calculation in molpro 2009.<br>
> > ><br>
> > > (i) in the manual,<br>
> > > <a href="http://www.molpro.net/info/current/doc/manual/node417.html" target="_blank">http://www.molpro.net/info/current/doc/manual/node417.html</a><br>
> > > it is said *<br>
> > ><br>
> > > *********<br>
> > > SAPT_FROZENA*Number of frozen electrons in the response calculations<br>
> ><br>
> > for<br>
> ><br>
> > > monomer A (default 0) ***************<br>
> > > If I understood correctly, it is the number of electrons (number of<br>
> > > orbital *2 in closed-shell case). But when I do a SAPT for neon dimer,<br>
> > > setting SAPT_FROZENA=6<br>
> > ><br>
> > > the output file said<br>
> > ><br>
> > ><br>
> > > Occupied space for monomer A: 5<br>
> > > Virtual space for monomer A: 87<br>
> > ><br>
> > > Occupied space for monomer B: 5<br>
> > > Virtual space for monomer B: 87<br>
> > > ? Error<br>
> > > ? frozena>noa!<br>
> > > ? The problem occurs in sapt_interface<br>
> > ><br>
> > > does it imply the FROZENA actually is the number of orbital to be<br>
> ><br>
> > frozen?<br>
> ><br>
> > > (ii) I set FROZENA=0,1,2; FROZENB=1, the E1tot+E2tot is invariant<br>
> > > respect with the frozen core set up. Why the frozen core does not<br>
> > > change the interaction energy?<br>
> > ><br>
> > > Here is an input file, if you need any other information, please let me<br>
> > > known<br>
> > ><br>
> > > *************************<br>
> > > memory,80,m<br>
> > > symmetry,nosym<br>
> > > geomtyp=xyz<br>
> > > geometry={<br>
> > > 2<br>
> > > title<br>
> > > Ne 0. 0. 0.<br>
> > > Ne 0. 0. 3.0}<br>
> > ><br>
> > > basis=avtz<br>
> > ><br>
> > > !wf records<br>
> > > ca=2101.2<br>
> > > cb=2102.2<br>
> > ><br>
> > ><br>
> > > !monomer A<br>
> > > dummy,2<br>
> > > {hf; save,$ca}<br>
> > > sapt;monomerA<br>
> > ><br>
> > > !monomer B<br>
> > > dummy,1<br>
> > > {hf; start,atdens; save,$cb}<br>
> > > sapt;monomerB<br>
> > ><br>
> > > !interaction contributions<br>
> > > {sapt,SAPT_FROZENA=6;intermol,ca=$ca,cb=$cb}<br>
> > ><br>
> > > *************************<br>
> > ><br>
> > ><br>
> > > Thank you very much in advance<br>
> > > Best regards<br>
> > > Cong Wang<br>
> > > Ph. D. Student<br>
> > ><br>
> > > Department of Chemistry<br>
> > > Laboratory for Instruction in Swedish<br>
> > > University of Helsinki<br>
> > > A.I. Virtanens plats 1<br>
> > > P.O. Box 55<br>
> > > FI-00014 University of Helsinki<br>
> > > FINLAND<br>
> ><br>
> > --<br>
> > --------------------------------------------------<br>
> > Andreas Hesselmann<br>
> > Institut für Physikalische und Theoretische Chemie<br>
> > Universität Erlangen<br>
> > Egerlandstraße 3<br>
> > 91058 Erlangen / Germany<br>
> > Phone: +49 9131/85-25021<br>
> > E-Mail: <a href="mailto:andreas.hesselmann@chemie.uni-erlangen.de" target="_blank">andreas.hesselmann@chemie.uni-erlangen.de</a><br>
> > -------------------------------------------------<br>
> > _______________________________________________<br>
> > Molpro-user mailing list<br>
> > <a href="mailto:Molpro-user@molpro.net" target="_blank">Molpro-user@molpro.net</a><br>
> > <a href="http://www.molpro.net/mailman/listinfo/molpro-user" target="_blank">http://www.molpro.net/mailman/listinfo/molpro-user</a><br>
<br>
</div></div>--<br>
<div><div></div><div>--------------------------------------------------<br>
Andreas Hesselmann<br>
Institut für Physikalische und Theoretische Chemie<br>
Universität Erlangen<br>
Egerlandstraße 3<br>
91058 Erlangen / Germany<br>
Phone: +49 9131/85-25021<br>
E-Mail: <a href="mailto:andreas.hesselmann@chemie.uni-erlangen.de" target="_blank">andreas.hesselmann@chemie.uni-erlangen.de</a><br>
-------------------------------------------------<br>
_______________________________________________<br>
Molpro-user mailing list<br>
<a href="mailto:Molpro-user@molpro.net" target="_blank">Molpro-user@molpro.net</a><br>
<a href="http://www.molpro.net/mailman/listinfo/molpro-user" target="_blank">http://www.molpro.net/mailman/listinfo/molpro-user</a><br>
</div></div></blockquote></div><br>