CCL:G: G- How to retain the symmetry in a SCF calculation ?

From: xunlei ding <dingxunlei*o*gmail.com>
Subject: CCL:G: G- How to retain the symmetry in a SCF calculation ?
Date: Fri, 13 Feb 2009 16:41:43 +0800

 Sent to CCL by: xunlei ding [dingxunlei.:.gmail.com]
 Dear CCLers,
 In the manual of G03, the key word "SCF= Symm" is discribed as below:
 Retain all symmetry constraints: make the number of occupied orbitals
 of each symmetry type (abelian irreducible representation) match that
 of the initial
 guess. Use this option to retain a specific state of the wavefunction
 throughout the calculation. It is the default only for GVB
 calculations.
 But sometimes it doesn't work and the last state is different from the
 initial state.
 Could you give me more suggestions on how to retain the symmetry in a
 SCF calculation?
 Thanks!
 Best regards,
 Ding