CCL:G: Questions about SAC-CI calculations.

From: "Huo-Lei Peng" <horaldraman+/-gmail.com>
Subject: CCL:G: Questions about SAC-CI calculations.
Date: Sat, 25 Apr 2009 02:54:25 -0400

 Sent to CCL by: "Huo-Lei  Peng" [horaldraman : gmail.com]
 Hi All:
 Recently, I'v been working on the calculations on a doublet radical, which has
 11 carbon, nitrogen
 or oxygen atoms, using SAC-CI in Gaussian 03. It looks SAC-CI needs a lot of
 disk space and
 computer resource. In my case, the computation generated a huge rwf or scr file
 (up to several
 hundred GB) and failed finally. Could you give me any suggestion?  Here is the
 input:
  %nprocshared=4
  %mem=16GB
  %rwf=1.rwf,30gb,2.rwf,30gb,3.rwf,30gb,4.rwf,30gb,5.rwf,30gb,6.rwf,-1
  # SAC-CI=(Full, MaxR2Op=1000000, AnionDoublet=(Nstate=3))/6-31G(d) ROH
  #P GFINPUT IOP(6/7=3)
  ----------------------------------------------------------------------
 BTW, if I use CASSCF to calculate the doublet radical, how to select the active
 space? Initial open-
 shell calculation gave me alpha and beta orbitals. So how to select the orbitals
 in this case.
 Any suggestions will be highly appreciated
 Thanks.
 Huo-Lei Peng
 Department of Chemistry
 The Ohio State University
 100 W. 18 Avenue
 Columbus, OH 43210