From chemistry-request@server.ccl.net Mon Apr 29 12:00:52 2002 Received: from lua.ifi.unicamp.br ([143.106.6.13]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g3TG0pA23994 for ; Mon, 29 Apr 2002 12:00:51 -0400 Received: by lua.ifi.unicamp.br (Postfix, from userid 106) id 0A7FEA952; Mon, 29 Apr 2002 13:00:40 -0300 (BRT) Received: from posdyn11.ifi.unicamp.br (posdyn11.ifi.unicamp.br [143.106.128.205]) by lua.ifi.unicamp.br (Postfix) with ESMTP id 25B0F5501 for ; Mon, 29 Apr 2002 13:00:39 -0300 (BRT) Message-Id: <5.1.0.14.0.20020429124821.00aa14c8@lua.ifi.unicamp.br> X-Sender: dasf@lua.ifi.unicamp.br X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Mon, 29 Apr 2002 13:02:55 -0300 To: CHEMISTRY@ccl.net From: "Demetrio A. da Silva Filho" Subject: GVB calculation in Gaussian'98 Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="=====================_1303687==_.ALT" X-AntiVirus: scanned for viruses by AMaViS 0.2.1 (http://amavis.org/) --=====================_1303687==_.ALT Content-Type: text/plain; charset="us-ascii"; format=flowed Dear CCL'ers, I am trying to perform a GVB calculation in Gaussian'98. The basic idea is to create just one GVB pair taking one electron from HOMO-1 one from LUMO. All the orbitals below the pair will be considered as closed shells and will not enter in the calculation. The system will be forced to be singlet. I was able to run that calculation in GAMESS, but the results are not consistent, so I want to do the same calculation in Gaussian'98. But I could not figure out which keywords I must use in order to do the same thing using Gaussian'98. Using Gamess, I just need to run a Hartree-Fock calculation to have a guess for the orbitals and then I use the keywords $SCF NCO=88 NSETO=2 NO(1)=1,1 $END To create the GVB pair and, freezing all orbitals below the HOMO and the keywords: $GUESS GUESS=moread norb=90 NORDER=1 $END $guess iorder(88)=89 iorder(89)=88 $end To change the HOMO-1 orbital (N=88) into HOMO (N=89). Then, at the end, I will have just one GVB pair composed by an electron > from HOMO-1 and one from LUMO. Does anybody knows how can I do the same thing using Gaussian'98? Thanks in advance and have a nice day! Demetrio Filho --=====================_1303687==_.ALT Content-Type: text/html; charset="us-ascii" Dear CCL'ers,

I am trying to perform a GVB calculation in Gaussian'98. The basic idea is to create
just one GVB pair taking one electron from HOMO-1 one from LUMO. All the orbitals below the pair
will be considered as closed shells and will not enter in the calculation. The system will be forced to be singlet.

I was able to run that calculation in GAMESS, but the results are not consistent, so
I want to do the same calculation in Gaussian'98. But I could not figure out which keywords I must use in order
to do  the same thing using Gaussian'98.

Using Gamess, I just need to run a Hartree-Fock calculation to have a guess for the orbitals
and then I use the keywords

$SCF NCO=88 NSETO=2 NO(1)=1,1 $END

To create the GVB pair and, freezing all orbitals below the HOMO and the keywords:

$GUESS  GUESS=moread norb=90 NORDER=1 $END                                    
$guess iorder(88)=89 iorder(89)=88 $end                                       

To change the HOMO-1 orbital (N=88) into HOMO (N=89).

Then, at the end, I will have just one GVB pair composed by an electron
> from HOMO-1 and one from LUMO.

Does anybody knows how can I do the same thing using Gaussian'98?

Thanks in advance and have a nice day!

Demetrio Filho
 --=====================_1303687==_.ALT--