Subject: Re: CCL:Fixed MOs in SCF calculation

From: [email-masked]
Date: Mon, 1 Mar 1999 10:15:10 +0100

You wrote :

<x>
<x>Hello,
<x>
<x>I wanted to know if it is possible to fix some MOs in SCF calculation,
<x>say, I provide the required MO coefficients in the input file, and I
<x>want them hold unchanged and get solutions of other MOs.
<x>
<x>Thanx,
<x>
<x>P. Lin
<x>

Dear P. Lin,

just have a look at paper : X. ASSFELD, and J.-L. RIVAIL, Chem. Phys. Lett.
263, (1996) 100-106.

In this paper paper you will find a general formalism to perform SCF calculations
with frozen orbitals. We called this method LSCF for "Local SCF" since only 
some molecular orbitals are variationnally optimized. These method was thought at
first for QM/MM technics on macromolecules but is applicable with no difficulty
to any type of molecular spinorbitals (occupied or not!). This is very simple
to implement in Gaussian, Gamess,...
If you need further informations I will be very glad to help.
Sincerely yours.

                                      ...Xav

Ast. Pr. Xavier Assfeld             [email-masked]
Laboratoire de Chimie theorique     (T) 33 3 83 91 21 49
Universite Henri Poincare           (F) 33 3 83 91 25 30
F-54506 Nancy BP 239                http://www.lctn.u-nancy.fr