[molpro-user] Re: Error: MCSCF not converged

[zhendong zhao]

You should use maxit card to overcome the problem. My final trial result
is: 
        RS2C            CASSCF          HF-SCF
   -139.05633715   -138.74835008   -138.60526163


 basis=avtz
 {hf;wf,17,1,1}
 {casscf;maxit,64;wf,17,1,1;state,2}
 {rs2c;wf,17,1,1;state,2}

ZZ

Quote:

Dear MOLPRO users,

I am running some calculations for CH3F+ (the lowset two energy states)
in the Ci (nosym) subgroup, hoping that CASSCF/RS2C will work out for
me and  finally give me the energies of the two states. However, there
always be an error in RS2C calculation after MCSCF. Sometimes this
error occurs in CASSCF calculation. Can you help me to solve this
problem? Thank you very much!

*******************************************************************************
The input file:

 ***,CH3F
 memory,400,m
  geometry={nosym;
            F
            C  F   r1
            H1 C   r2  F  e
            H2 C   r2  F  e  H1 120
            H3 C   r2  F  e  H1 -120
           }
 R1=  2.61448256
 R2=  2.14453883
 E =109.24490107
  
 basis=avtz
 {hf;wf,17,1,1}
 {casscf;wf,17,1,1;state,2}
 {rs2c;wf,17,1,1;state,2}
*********************************************************************************

*********************************************************************************
The error in output file:

1PROGRAM * RS2 (Multireference RS Perturbation Theory)     Authors:
H.-J. Werner (1993), P. Celani (1998)


 Convergence thresholds:  THRVAR = 1.00D-08  THRDEN = 1.00D-06

 Number of optimized states:  1  Roots:   1
 Number of reference states:  1  Roots:   1

 Reference symmetry:                   1   Doublet 
 Number of electrons:                 17
 Maximum number of shells:             7
 Maximum number of spin couplings:   429

 Reference space:    10248 conf    38304 CSFs
 N elec internal:    19855 conf    76230 CSFs
 N-1 el internal:    24068 conf   158994 CSFs
 N-2 el internal:    25653 conf   290763 CSFs

 Number of electrons in valence space:                     13
 Maximum number of open shell orbitals in reference space:  9
 Maximum number of open shell orbitals in internal spaces: 13


 Number of core orbitals:           2 (   2   0 )
 Number of active  orbitals:       11 (   8   3 )
 Number of external orbitals:      60 (  38  22 )
 
 Molecular orbitals read from record     2140.2  Type=MCSCF/NATURAL
(state averaged)

 ?Error: MCSCF not converged. This error exit can be avoided using the
IGNORE_ERROR option on the ORBITAL directive

***********************************************************************************************************

I have tried several times on this suggestion, but failed. How can I
overcome this error?


 Yours, Yong