[molpro-user] FCI iteration termination: expansion set singular
sfiedler at csun.edu
Tue Jan 10 23:22:47 GMT 2012
Dear Molpro users:
I am conducting a series of FCI calculations of multiple states of the
He2* dimer at various internuclear separation distances with a large
basis set. Calculations of small separation distances (< 2 bohr)
terminate after a number of FCI iterations with the following error:
"expansion set singular". Prior to this error, the lowest root appears
to be converging rapidly to minus infinity.
Insight or advisement would be appreciated.
Department of Chemistry and Biochemistry
California State University, Northridge
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