[molpro-user] MRCI with nosym option used not correct reference function from CAS

[Hans-Joachim Werner]

For some reason it finds a wrong reference state.
Try:

{mrci;pspace,1
orbit,2240.2;
wf,16,1,2}


this works for me.

Joachim

---
Prof. Dr. Hans-Joachim Werner
Institut für Theoretische Chemie
Universität Stuttgart
Pfaffenwaldring 55
70569 Stuttgart, Germany
e-mail: werner at theochem.uni-stuttgart.de




> Am 26.06.2017 um 11:40 schrieb David Danovich <david.danovich at gmail.com>:
> 
> Hello,
> 
> I am trying to do freq calculation for F2(2+) molecule at MRCI level. For freq calculation I need to do CAS and MRCI without symmetry. As a first step, I have done CAS and MRCI with symmetry and got correct energies. Then I continue with nosym. For CAS I got the same energy as in the case with symmetry but for MRCI not.  For MRCI (nosym) calculation, program uses not correct reference energy and produces not correct total energy of MRCI. I was trying to use many option but without success. 
> 
> Here is an input
> 
>  ***,F2(2+)
>  memory,350,m
>  gprint,orbital,civector;
>  gthresh,energy=1.d-10
>   r  = 1.6099 ang;
>  geometry={F1;                                                                   !z-matrix geometry input
>            F2,F1,r;
>            }
>  
>  basis=aug-cc-pVTZ
>  
>  {hf;accu,16;
>  wf,16,4,2}
>  
>  {multi;
>  maxit,39;
>  wf,16,4,2;
>  orbital,2140.2}
>  
>  {mrci;
>  orbit,2140.2;
>  wf,16,4,2}
>  
>  symmetry,nosym
>  
>  {hf;accu,16;
>  wf,16,1,2}
>  
>  {multi;
>  start,2140.2;
>  maxit,39;
>  wf,16,1,2;
>  orbital,2240.2}
>  
>  {mrci;
>  orbit,2240.2;
>  wf,16,1,2}
>  
> {frequencies;
>  symm,no}
> 
> 
> 
> Because output is too large I just put here part of it.
> 
> Here is energy  from symmetric CASSCF
> 
> Results for state 1.4
>  =====================
> 
>  !MCSCF STATE 1.4 Energy             -197.330948763044
> 
> 
> Here is results from non symmetric CASSCF (Both symm and nosymm have the same energies)
> 
> Results for state 1.1
>  =====================
> 
>  !MCSCF STATE 1.1 Energy             -197.330948763044
> 
> 
> Here is reference wavefunction from symmetric MRCI (it is the same as CASSCF)
> 
>  Reference wavefunction optimized for reference space (refopt=1)
> 
>  State     Reference Energy 
>    1        -197.33094876
> 
> 
> and here is energy
> 
>  !MRCI STATE 1.4 Energy              -197.671580012360
> 
> 
> Here is reference wavefunction from nonsymmetric MRCI (it is different from CASSCF)
> 
>  Reference wavefunction optimized for reference space (refopt=1)
> 
>  State     Reference Energy 
>    1        -197.31016250
> 
> and the total energy is different from symmetric calculations
> 
> !MRCI STATE 1.1 Energy              -197.646905059678
> 
> 
> What I am doing wrong in nosym MRCI calculation and what I need to do in order to get the right energy with nosym MRCI?
> 
> Thank you  David
> 
> -- 
> <image003.jpg>Dr. David Danovich
> The Lise Meitner Minerva Center for Computational Quantum Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem,  Edmond J. Safra Campus - Givat Ram, 9190401 Jerusalem, Israel  
> http://yfaat.ch.huji.ac.il/david.html, e-mail: david.danovich at mail.huji.ac.il
> FAX:(+972)-2-6584033, Phone:(+972)-2-6586934(w),  Mobile:(+972)-544-768669
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