[molpro-user] What is PSPACE?

[Bhargava Anusuri]

Dear MOLPRO users,
                 I've been computing PESs and quite often my jobs get
terminated due to non-convergence at MULTI/CASSCF level citing
problems due to PSPACE i.e., either it's insufficient or not closed
under symmetry or higher than necessary. I used to try different
PSPACE values and get my job done but I never really understood the
rationale behind this. Can somebody tell me what exactly this PSPACE
is or at least point me in the direction where I can find any info on
this. I will be very grateful to your help.

Regards,
Bhargava Anusuri,
IIT Madras, India.