[molpro-user] CASPT2 error

Sham sham at theochem.uni-stuttgart.de
Thu Jan 6 19:30:26 GMT 2011

Dear Alexander,

You seem to be running rs2c calculations on excited states one by one. 
Each of these calculations go through an initial internal CI (from where 
the error comes). The calculation on 4-th state, the internal CI 
calculates 4 roots (by default all lower roots upto the reqested root).
It may be possible that 4-th and 5-th roots are nearly degenerate causing 
internal CI to converge slowly. Just check MCSCF state energies for 4-th 
and 5-th state to see if this is the case.

Apart from increasing maxiti (which is likely to work in this case), you 
may also try to use



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