[molpro-user] CASPT2 calculation too big

[Sarah Wilsey]

Hi,

We have a problem running a CASPT2 calculation on a large system  
using the RS2C keyword. The maximum number of basis functions has  
been set to 4095 which is the limit at compilation time but we still  
get the error message:

>>
>> Number of p-space configurations:   9
>>
>>  Reference wavefunction optimized for reference space (refopt=1)
>>
>>  State     Reference Energy
>>    1        -903.18666165
>>    2        -902.89530396
>>    3        -902.89159529
>>  n=                  4134   lvec=                  4095
>>  ? Error
>>  ? LVECT TOO SMALL
>>  ? The problem occurs in SMH
>>

Please could you let me know if it is safe to manually increase the  
value of the parameter lenvc in common/cvectr to be more than 4095 or  
is this likely to lead to problems?

Many thanks,

Sarah Wilsey




------------------------------------------------------------------------ 
--------------
Dr Sarah Wilsey
EPSRC National Service for Computational Chemistry Software
Department of Chemistry
Imperial College
London SW7 2AZ
Phone: 020 7594 1220      Fax: 020 7594 5804
URL: http://www.nsccs.ac.uk