Re: CCL:Freezing atoms-modredundant

[Aaron Deskins <ndeskins_at_ecn.purdue.edu>]

 Thanks for the replies. I think I found the problem. I needed the Nosymm
  keyword for the optimization to work properly. Thanks again!
 Aaron Deskins wrote:
>  Hello all,
>   I have (hopefully) a relatively simple question. I'm trying some
>  simple test calculations using Gaussian 98, but am running into a
>  little
>  problem freezing atom positions. Essentially I want to freeze a few
>  atoms, and allow others to relax. Below is a test file. The problem I
>  see is that the geometry optimization algorithm moves all atoms to the
>  same location on first pass and subsequently causes the program to
>  crash. I've tried different atoms and arrangements with no luck. Any
>  suggestions?  Thank you
>  # opt(maxcycle=200,modredundant) hf/lanl2dz scf(diis,maxcycle=300)
>  Title Card Required
>  0  3
>  c 0.0000000000 0.0000000000 0.0000000000
>  c 2.7718585823 0.0000000000 0.0000000000
>  c 0.0000000000 2.7718585823 0.0000000000
>  c 2.7718585823 2.7718585823 0.0000000000
>  1 f
>  2 f
>  3 f
 --
 Aaron Deskins
 Graduate Student
 Chemical Engineering
 Purdue University