CCL:G: starting guess from unrestricted DFT for CAS-SCF in G09

From: "Barbara Fresch" <bfresch%%ulg.ac.be>
Subject: CCL:G: starting guess from unrestricted DFT for CAS-SCF in G09
Date: Wed, 4 Jan 2012 12:39:03 -0500

 Sent to CCL by: "Barbara  Fresch" [bfresch^-^ulg.ac.be]
 hello everybody,
 i'm trying to obtain the CASSCF wavefunction of the ground state of a metal
 cluster with G09.
 I want to select the active space from the orbitals obtained by an unrestricted
 B3LYP optimization. I can also use those orbitals as starting guess for the
 CASSCF (I just use Guess=Read).
 Here where I'm confused: since from the unrestricted-DFT one obtains two set of
 orbitals (the alpha and the beta orbitals) while as far as i understood the
 CASSCF wavefunction is a combination of restricted determinants, how the initial
 guess is adapted? Does Gaussian use only e.g. the alpha set of orbitals?
 thanks in advance for your help.
 Barbara Fresch
 e-mail: bfresch\a/ulg.ac.be