[molpro-user] RS2 analytical gradients

Borys Szefczyk szefczyk at cartman.ch.pwr.wroc.pl
Sun Mar 6 19:40:27 GMT 2011

On Sun, Mar 06, 2011 at 09:14:08PM +0300, Konstantin Tokarev wrote:
> 06.03.2011, 19:58, "Borys Szefczyk" <szefczyk at cartman.ch.pwr.wroc.pl>:
> > Dear Molpro users & developers,
> >
> > I am trying to do some geometry optimizations using the RS2 program,
> > but I am facing the limitation of 32 active orbitals. At least for some
> > of my systems, freezing core orbitals would help, but the program says
> > that "RS2 gradients not possible with frozen core mcscf orbitals".
> > I am using Molpro 2009.1. Is there any way to use frozen orbitals and
> > calculate analytical CASPT2 gradients in Molpro? How about the most
> > recent version of the code? Any plans to implement this in the future?
> AFAIK you need 128-bit CPU to get 64 active orbitals limit :) It's algorithm
> limitation.

Dear Konstantin,

32 active orbitals would be fine for me. I was asking about CASPT2
analytical gradients with frozen core orbitals. I don't have access to
the most recent version of Molpro; perhaps it is implemented already?


  Molecular Modelling & Quantum Chemistry Group,
  Institute of Physical & Theoretical Chemistry,
  Wroclaw University of Technology

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