Paul started his career in molecular and materials modeling as a graduate student with Prof. Henry F. “Fritz” Schaefer, III, at the University of California, Berkeley, working on some of the early codes for direct configuration interaction (CI) and calculating first and second derivatives of the energy. These codes, which allowed better calculations and faster ways to find structures and calculate vibrational spectra, started Paul’s interest in developing better and better tools for simulating molecules and materials, as well as his life-long interest in harnessing the ever increasing power of computers to science. At the time, in the 1980s, computers were much more limited than they are now — a million or more times slower! However, they could nonetheless handle interesting scientific questions, and the growth has both been a challenge and exhilarating.
As these mergers occurred, Biosym/MSI pulled back from the materials market, so Paul left with Dr. John Harris to start Materials Design in 1998. Materials Design focussed heavily on materials simulations and databases, so for the next 18 years Paul had a hand in every aspect of commercial modeling, from code development to graphics to user interfaces and workflows, as well as a considerable amount of innovative science using the tools he was building. This experience rounded out Paul’s background, which include quantum chemistry for molecular systems, forcefields and MD for drug design as well as for polymers, and finally materials simulation using either forcefield approaches such as the embedded atom method (EAM) of periodic DFT with codes such as VASP.
In 2017, Paul brought this wealth of experience to MolSSI as the lead software scientist.