EOM-CCSD frequencies

[Peter Knowles]

The simple answer to this is that it cannot yet be done. There is code
in the geometry optimizer to use the contents of an arbitrary variable
as the objective function, and to compute numerical
gradients. Unfortunately, the analogous code for frequencies is not
written. It is planned to do it, but, as always, it's in a queue
behind some other things. You might also want to bear in mind that
such numerical frequency computations will be very expensive, and may
suffer from numerical problems arising from the double
differentiation.

Regards

Peter Knowles

martina at omega.physchem.kth.se wrote at 09:24 on 24 October 2000:
 > Hello Molpro users!
 > Have you tried to get frequencies at the EOM-CCSD level?
 > As to my knowledge, it is working only for the CCSD. During
 > the frequency evaluation, only the energy(1) is taken into account.
 > One can optimize structure at the EOM-CCSD level using option
 > variable,energy(2)
 > 
 > ....
 > int
 > hf
 > ccsd;maxiter,60
 > eom,1.2
 > eompar,maxiter=60
 > optg
 > variable,energy(2)
 > ....
 > 
 > What do you suggest to do to solve my problems? I appreciate your help.
 > 
 > Martina
 > 
 > ********************
 > Martina Bittererova
 > Royal Institute Of Technology
 > Department of Physical Chemistry
 > SE-100 44 Stockholm
 > Sweden
 > 

-- 
Prof. Peter J. Knowles              
Email P.J.Knowles at bham.ac.uk  Phone +44-121-414-7472  Fax +44-121-414-7471
School of Chemistry, Univ. of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
WWW http://www.tc.bham.ac.uk/~peterk/