J. Philip Haupt

I am a computational scientist working in the intersection of physics, computer science, and chemistry. I am currently employed as a postdoctoral fellow at the Max Planck Institute for Solid State Research in Stuttgart, Germany. Prior to this, I graduated with my PhD from the same institute under the direct supervision of director Prof Ali Alavi in the electronic structure theory department. My dissertation focused on combining real- and orbital-space methods in quantum chemistry, specifically in the form of the transcorrelated and full configuration interaction quantum Monte Carlo methods. I am interested in shifting gears in the next step of my career by studying larger systems and making a more direct societal impact using my technical knowledge. I am especially in doing this with data-driven methods.

I have a varied-yet-in-depth experience. I hold an honours degree from the University of British Columbia in physics and mathematics with a minor in computer science. With this degree, I also participated in the co-operative education program where I collected valuable experience doing research in machine learning for physics (atomic physics, polymer sequencing, and STM data analysis) as well as work as a data analyst for the Canadian police. After, I started a PhD in theoretical optical physics (solar cell simulations) at the University of Toronto, but ultimately found out this wasn’t for me and switched to the Max Planck Institute to finish a PhD in computational chemistry, where I had previously done a coop work term.

For more information, please use the links in the header of the website. For example, to see more about my professional experience, see my (shortened) CV. Also feel free to reach out to me via email or LinkedIn.

selected publications

JCP
Optimizing Jastrow Factors for the Transcorrelated Method

J. Philip Haupt, Seyed Mohammadreza Hosseini, Pablo López Ríos, and 3 more authors

The Journal of Chemical Physics, 2023

Abs DOI Bib

We investigate the optimization of flexible tailored real-space Jastrow factors for use in the transcorrelated (TC) method in combination with highly accurate quantum chemistry methods, such as initiator full configuration interaction quantum Monte Carlo (FCIQMC). Jastrow factors obtained by minimizing the variance of the TC reference energy are found to yield better, more consistent results than those obtained by minimizing the variational energy. We compute all-electron atomization energies for the challenging first-row molecules C2, CN, N2, and O2 and find that the TC method yields chemically accurate results using only the cc-pVTZ basis set, roughly matching the accuracy of non-TC calculations with the much larger cc-pV5Z basis set. We also investigate an approximation in which pure three-body excitations are neglected from the TC-FCIQMC dynamics, saving storage and computational costs, and show that it affects relative energies negligibly. Our results demonstrate that the combination of tailored real-space Jastrow factors with the multi-configurational TC-FCIQMC method provides a route to obtaining chemical accuracy using modest basis sets, obviating the need for basis-set extrapolation and composite techniques.
@article{hauptOptimizing2023, title = {{Optimizing {{Jastrow}} Factors for the Transcorrelated Method}}, author = {Haupt, J. Philip and Hosseini, Seyed Mohammadreza and L\'opez R\'ios, Pablo and Dobrautz, Werner and Cohen, Aron and Alavi, Ali}, journal = {The Journal of Chemical Physics}, volume = {158}, number = {22}, pages = {224105}, year = {2023}, doi = {10.1063/5.0147877}, }