Subject: Matching classical & abinitio normal modes

From: Vani Krishna <vakri2002 !=! yahoo.com>
Date: Tue, 26 Apr 2005 19:43:49 -0700 (PDT)

Hello:

I have a question regarding the matching of normal
modes for optimizations to determine the intra bond
force constants. How to resolve a one to many mapping
between the two? Some of the classical frequencies
match more than one abinitio ferquencies, and some are
not matched at all. Ofcourse i hope that during the
optimization process this matching might improve, but
I want to make sure that iam doing the most
appropriate matching. And also should every frequency
be matched?

also what kind of scaling of frequencies is used for
HF and DFT  before comparing them with classical
frequencies? Any references would be great. Iam new to
force-field development and this would help me a lot.

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com