Posted by Balazs Hajgato on September 19, 2003 at 03:48:19:
Dear Molcas Developers and Users,
I try to calculate Electron affinity of a molecule, which in D3h symmetry. The cas calculation were run perfectly and I do not have forbidden mixings. The unpaired electron is on a degenerate orbital so I have calculated state average CAS (in Cs symmetry). Is there possible to calculate caspt2 for this average cas state? I have tried multi state caspt2 but I get two (almost) equal energy state, but the occupancies were wrong. (broken symmetry). I have also tried MRSDCI calculation but my system is quite large and I always get the following error message:
SORTB Error: NOVST+IACMIN-1+NOVM > MCHAIN
NOVST = 4049
IACMIN= 1
NOVM = 67896
MCHAIN= 49151
So I would like to know is there possible to increase the MCHAIN value in the source? And if it is possible will my calculation run within an acceptable time? (The caspt2 was run in 1 day, and I think 2-4 weeks is still acceptable runtime)
I welcome any suggestion.
Regards,
Balazs Hajgato
e-mail hajgato(at)iris.inc.bme.hu