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

Stochastic coupled cluster theory.
AJW Thom
Phys Rev Lett
(2010)
105
LOBA: a localized orbital bonding analysis to calculate oxidation states, with application to a model water oxidation catalyst.
AJW Thom, EJ Sundstrom, M Head-Gordon
Physical Chemistry Chemical Physics
(2009)
11
Hartree-Fock solutions as a quasidiabatic basis for nonorthogonal configuration interaction.
AJW Thom, M Head-Gordon
The Journal of chemical physics
(2009)
131
Fermion Monte Carlo without fixed nodes: A game of life, death, and annihilation in Slater determinant space
GH Booth, AJW Thom, A Alavi
Journal of Chemical Physics
(2009)
131
Locating multiple self-consistent field solutions: an approach inspired by metadynamics.
AJW Thom, M Head-Gordon
Phys Rev Lett
(2008)
101
Electron correlation from path resummations: the double-excitation star.
AJW Thom, GH Booth, A Alavi
Phys Chem Chem Phys
(2008)
10
Stochastic perturbation theory: a low-scaling approach to correlated electronic energies.
AJW Thom, A Alavi
Physical Review Letters
(2007)
99
Path Resummations and the Fermion Sign Problem
A Alavi, AJW Thom
COMPUTER SIMULATIONS IN CONDENSED MATTER SYSTEMS: FROM MATERIALS TO CHEMICAL BIOLOGY, VOL 1
(2006)
703
A combinatorial approach to the electron correlation problem - art. no. 204106
AJW Thom, A Alavi
J Chem Phys
(2005)
123

Research Group

Research Interest Group

Telephone number

01223 336470

Email address

College