cclib/cclib — pull request #62 by arsphenamine (2014-03-13 00:49:53+00:00)
Title: Energy conversions in GAMESS

This arose from what I suspect is a conversion error in GAMESS zero point energy listing. That is someone else's problem, never to be fixed as the Gordon Group has much more important things on its collective mind.

While extracting some large cluster (As4) SCF energies, I noticed minute conversion errors when moving from Hartree -> eV -> Hartree. They tended to be small, ca. 0.1 milliHartrees or 0.26 kJ/mol.

The available conversions between cm-1, eV, Hartrees, kCal, and kJ are exhaustive in this fork.

Updating utils.convertor() code to NIST's 2010 CODATA factors with as many decimal places as were published, the conversion 'errors' diminished to the 1-10 microHartree range, low enough to please anyone running W1-W4 composite methods.

Please give it a glance.