Problems with calculating gradients for EOM-CC energy

[Tatiana Korona]

On Thu, 14 Feb 2002, Evgeniy Gromov wrote:

> Dear Sir,
> 
> Could You help me to overcome the following problem. I want to calculate
> (numericaly)
> gradinets of excited state for EOM-CCSD energy  using such option as "
> FORCE,NUMERICAL,STARTCMD=command ".
> But I do not manage to specify the excited state energy as variable. The
> program (molpro2002.1) 
> calculates gradients for ground state CCSD energy in any case. I tried
> to set VARIABLE=ENERGY(2)
> (in above mentioned construction ) but it got no effect. I used for my
> "experiments" simple example:
> 
> ***,N2 test EOM-CCSD
>  file,1,n2.int,new;
>  file,2,n2.wfu,new;
>  file,3,n2.res,new;
>  basis=cc-pvdz
>  geometry={
> !nosym
>  n1;
>  n2,n1,2.068
>  }
> !
>  hf
>  wf,14,1,0;
>  orbprint,20
> !
> ! EOM-CC
> !
>  ccsd;
>  eom,5.1;
>  forces,numerical,startcmd=hf
>  coord,3n
>  variable=energy(2)
> ---
> 
> 
> I will very appreciate you for any help.

Try:

 ccsd;
 eom,5.1;
 e_exc=energy(2)
 forces,numerical,startcmd=hf
 coord,3n
 variable,e_exc

Tatiana Korona