Proton Affinitiy Calculation from GAMESS Outputs

This script is used for rapid calculation of proton affinity values (enthalpy of separation of a proton to affinity, typically in the gas-phase) from GAMESS outputs.

Essentially the energies of the protonated vs the unprotonated species are calculated and subtracted to give the energy value. The calculation was based on a summer school tutorial organised by the Theoretical and Computational Biophysics Group from the University of Illinois at Urbana-Champaign but also after discussion with Dr. Gordon Driver.

The script was published in a recent article on the prediction of cellulose dissolution capabilties of acid-based conjugate ionic liquids.