University Lecturer

Alex Thom is a University Professor in Theoretical Chemistry in the University of Cambridge. His research interests are in Theoretical and Computational Chemistry, specializing in method and software development.

Current projects involve the calculation of accurate electronic energies using Monte Carlo techniques, the description of excited states of medium-large molecules (from chromophores to single-molecule magnets) using new methodologies, and the application of Quantum Chemical Algorithms on Quantum Computers.

I am also a developer of the HANDE QMC package (version 1.6 released June 2022) which (amongst many features) performs Full Configuration Interaction Quantum Monte Carlo and Coupled Cluster Monte Carlo on molecular and solid-state systems, and am happy to be contacted with questions about using this or potential applications.

As part of the EXTRA Consortium, we have been looking at the development processes involved in writing scientific software on modern reconfigurable architectures (principally FPGAs), and currently have projects implementing Quantum Monte Carlo methods on these architectures.

I am also part of the Cambridge Leverhulme Centre for Life in the Universe researching prebiotic reaction networks and the original of chirality.

More information about my research and research group is available on the group website.

PhD and MPhil Positions

If you are interested in pursuing an MPhil or PhD in my group, please contact my secretary, sending a CV by email.  Applications to begin October 2026 are now open. Applications for scholarship funding have now closed, but applicants with external funding will still be able to apply until February 2026 (for MPhil) and May 2026 (for PhD). 
 

I am part of the Centre for Scientific Computing as well as the Leverhulme Centre for Life in the Universe which offer some funded PhD positions, and I am happy to accept applicants for the MPhil in Scientific Computing and also Chemistry. Some example project ideas can be found here.

Dr Thom discusses his research


Publications

General Approach for Multireference Ground and Excited States Using Nonorthogonal Configuration Interaction.
HGA Burton, AJW Thom
Journal of chemical theory and computation
(2019)
15
Using SCF metadynamics to extend density matrix embedding theory to excited states
HK Tran, T Van Voorhis, AJW Thom
The Journal of chemical physics
(2019)
151
Preconditioning and Perturbative Estimators in Full Configuration Interaction Quantum Monte Carlo
NS Blunt, AJW Thom, CJC Scott
Journal of Chemical Theory and Computation
(2019)
15
PT-Symmetry in Hartree--Fock Theory
HGA Burton, AJW Thom, P-F Loos
J Chem Theory Comput
(2019)
15
Automated Acceleration of Dataflow-Oriented C Applications on FPGA-Based Systems
F Peverelli, M Rabozzi, S Cardamone, E Del Sozzo, AJW Thom, MD Santambrogio, L Di Tucci
2019 27TH IEEE ANNUAL INTERNATIONAL SYMPOSIUM ON FIELD-PROGRAMMABLE CUSTOM COMPUTING MACHINES (FCCM)
(2019)
00
The HANDE-QMC Project: Open-Source Stochastic Quantum Chemistry from the Ground State Up
JS Spencer, NS Blunt, S Choi, J Etrych, M-A Filip, WMC Foulkes, RST Franklin, WJ Handley, FD Malone, VA Neufeld, R Di Remigio, TW Rogers, CJC Scott, JJ Shepherd, WA Vigor, J Weston, R Xu, AJW Thom
Journal of chemical theory and computation
(2019)
15
Diagrammatic Coupled Cluster Monte Carlo.
CJC Scott, R Di Remigio, TD Crawford, AJW Thom
The Journal of Physical Chemistry Letters
(2019)
10
Field-programmable gate arrays and quantum Monte Carlo: Power efficient coprocessing for scalable high-performance computing
S Cardamone, JRR Kimmitt, HGA Burton, TJ Todman, S Li, W Luk, AJW Thom
International Journal of Quantum Chemistry
(2019)
119
Complex adiabatic connection: A hidden non-Hermitian path from ground to excited states.
HGA Burton, AJW Thom, P-F Loos
The Journal of chemical physics
(2019)
150
Exciting determinants in Quantum Monte Carlo: Loading the dice with fast, low memory weights
VA Neufeld, AJW Thom
Journal of Chemical Theory and Computation
(2019)
15

Research Group

Research Interest Group

Telephone number

01223 336470

Email address

College