difficulty with open-shell molecule/Chen

[molpro-support at tc.bham.ac.uk]

> On Date: Wed, 22 Dec 1999 18:03:20 +0100 (CET) Chen Yu <cheny at mailer.uni-marburg.de> wrote:
> 
> > Dear Sir:
> > 
> > Could you help me to solve my problem in using Molpro Program?
> > 
> > I have difficulty to define the orbital of open-shell molecule with
> > Molpro96.4. Must one define the electrons with alpha spin and beta spin
> > seperatedly in the case of UHF? Here is my example:
> > ==================================================================
> >  Orbital Symmetries:
> >    Alpha Orbitals:
> >        Occupied  (A') (A") (A') (A') (A") (A') (A') (A') (A') (A")
> >                  (A') (A") (A') (A') (A') (A") (A') (A') (A') (A")
> >                  (A') (A") (A') (A") (A') (A") (A') (A') (A") (A")
> >                  (A') (A') (A') (A")
> >    Beta Orbitals:
> >        Occupied  (A') (A") (A') (A') (A") (A') (A') (A") (A') (A')
> >                  (A') (A") (A') (A') (A') (A") (A') (A') (A") (A')
> >                  (A") (A') (A") (A') (A') (A") (A") (A') (A') (A")
> >                  (A')   
> > ==================================================================
> > I know that the total alpha orbitals are 22 A' and 12 A"
> > The total alpha orbitals are 20 A' and 11 A"
> > And then I type the input as below:
> > ==================================================================
> > uhf-scf;         ! UHF calculation
> > wf,65,2,3;       ! the state is 4A" (in Cs sym.)
> > occ,22,12;       ! or occ,22,12,,20,11 ????
> > closed,20,11;    ! or closed,20,11,,20,11 ????
> > open,2.1,1.2;    ! two electrons are in A' and one electron is in A"
> > maxit,200;
> > uccsd(t);
> > maxiter,100;
> > core,4,2;        ! core electron of 4A' and 2A" are not included ..
> > ==================================================================
> > Is it correct or not?
> > The SCF doesn't converge. With other programs such as Gaussian and 
> > ACES it has no problem to converge for same basis set. So I guess 
> > something is wrong with my input. Because Molpro is 
> > more faster than others I would like to do my all CCSD(T) calculations 
> > only with Molpro. Could you give me some ideas for this situation?
> > Secondly, if it is in C1 symmetry, is it correct to input
> > ===========
> > wf,65,1,3;
> > ...
> > core,6;
> > ===========
> > ?
> > If it is necessary I could send you a full infut file. But I prefer 
> > that it is wrong only with understanding of manual about the input file.
> > Thank you very much for your help. Merry Christmas!
> > 
> > Yu Chen
> > 
> > 
> > 
>