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robashaw / libecpint

A C++ library for the efficient evaluation of integrals over effective core potentials.
MIT License
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Error message "Failed to converge:" in calculation on AuI #21

Closed thomas-dresselhaus closed 3 years ago

thomas-dresselhaus commented 3 years ago

In a calculation on AuI, multiple outputs of an error message "Failed to converge:" appeared, which seem to originate from a grid integration. The program continues to run, but the resulting energy seems to be off by about 1 mHartree.

robashaw commented 3 years ago

Please can you give enough detail (bond distance, basis sets, code version) so that I can reproduce the error. The quadrature is adaptive so should only fail to converge if something is going seriously wrong.

thomas-dresselhaus commented 3 years ago

Of course, sorry for not providing this information straight away.

The calculation is a standard Hartree--Fock calculation on AuI in the Def2-SVP basis set (as obtained from the widely used basis set exchange). The calculation shows the above error for various bond lengths (2, 3, 4 Angstrom, and also the optimal bond length of 2.405 Angstrom).

The libecpint version used is the most recent master version, i.e. commit fa8df43c0adc7587a4a44b87fc9567a33dcc003d.

robashaw commented 3 years ago

This issue is now resolved in the new patch (pr #23). I get no more convergence issues, and an RHF energy that agrees with molpro to the microhartree.