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#51 nij=0 when interatomic distance small
When trying to do HF calculation of the interatomic potential at very small distances (e.g. O-O 0.001 angs apart), mpqc crashes due to nij = 0 when PetiteList::init() computes lamij_[ij] = (char) (ng_/nij); I tried giving lamij_[ij] different values (e.g. 0, 1000) when nij=0 but then it crashes somewhere else on an allocation error. Also tried different bases. Am I away from mpqc application range?
Discussion
Anonymous
Example of simple input file
Possible answer: when facing a similar problem in psi3, I found that changing LINDEP_CUTOFF (which is the "threshold below which basis functions are considered linearly dependent") to 1E-9 instead of 1E-6, it solved the problem, at least to distances down to 0.001 angs. psi3 still says that "Near-linear dependencies in the basis were eliminated. Proceed at your own risk!", but the potential at short distances correctly tends towards Z_1 Z_2 / r. There might be a similar parameter in mpqc.