Subject: g98 Intrinsic reaction calculation

From: "Curtis Hoganson" <[email-masked]>
Date: Mon, 13 Dec 1999 10:35:48 -0500

Greetings,
  I have used gaussian98 to optimize to a putative transition state, to
test the stationary point with a frequency calculation, and to perform
an intrinsic reaction coordinate calculation to determine that the
reactant and product are those desired. For these jobs, a single
checkpoint file was used.
  I would now like to reoptimize the transition state using a larger
basis set, so my questions are: does the checkpoint file after the irc
calculation still contain the force constant information for the
transition state geometry, and if so, what input command can I use to
specify that the correct (cartesian) force constants should be read from
the checkpoint file? 
  [Clearly, I could have avoided this problem by copying and saving the
checkpoint file from the frequency calculation, and in future will do
so. ]
  Thanks for any help.

Curtis Hoganson
[email-masked]
Dept of Chemistry, University of Delaware