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

Holomorphic Hartree-Fock Theory and Configuration Interaction.
HG Hiscock, AJW Thom
J Chem Theory Comput
(2014)
10
Advances in molecular quantum chemistry contained in the Q-Chem 4 program package
Y Shao, Z Gan, E Epifanovsky, ATB Gilbert, M Wormit, J Kussmann, AW Lange, A Behn, J Deng, X Feng, D Ghosh, M Goldey, PR Horn, LD Jacobson, I Kaliman, RZ Khaliullin, T Kuś, A Landau, J Liu, EI Proynov, YM Rhee, RM Richard, MA Rohrdanz, RP Steele, EJ Sundstrom, HL Woodcock, PM Zimmerman, D Zuev, B Albrecht, E Alguire, B Austin, GJO Beran, YA Bernard, E Berquist, K Brandhorst, KB Bravaya, ST Brown, D Casanova, C-M Chang, Y Chen, SH Chien, KD Closser, DL Crittenden, M Diedenhofen, RA DiStasio, H Do, AD Dutoi, RG Edgar, S Fatehi, L Fusti-Molnar, A Ghysels, A Golubeva-Zadorozhnaya, J Gomes, MWD Hanson-Heine, PHP Harbach, AW Hauser, EG Hohenstein, ZC Holden, T-C Jagau, H Ji, B Kaduk, K Khistyaev, J Kim, J Kim, RA King, P Klunzinger, D Kosenkov, T Kowalczyk, CM Krauter, KU Lao, AD Laurent, KV Lawler, SV Levchenko, CY Lin, F Liu, E Livshits, RC Lochan, A Luenser, P Manohar, SF Manzer, S-P Mao, N Mardirossian, AV Marenich, SA Maurer, NJ Mayhall, E Neuscamman, CM Oana, R Olivares-Amaya, DP O’Neill, JA Parkhill, TM Perrine, R Peverati, A Prociuk, DR Rehn, E Rosta, NJ Russ, SM Sharada, S Sharma, DW Small, A Sodt, T Stein, D Stück, Y-C Su, AJW Thom, T Tsuchimochi, V Vanovschi, L Vogt, O Vydrov, T Wang, MA Watson, J Wenzel, A White, CF Williams, J Yang, S Yeganeh, SR Yost, Z-Q You, IY Zhang, X Zhang, Y Zhao, BR Brooks, GKL Chan, DM Chipman, CJ Cramer, WA Goddard, MS Gordon, WJ Hehre, A Klamt, HF Schaefer, MW Schmidt, CD Sherrill, DG Truhlar, A Warshel, X Xu, A Aspuru-Guzik, R Baer, AT Bell, NA Besley, J-D Chai, A Dreuw, BD Dunietz, TR Furlani, SR Gwaltney, C-P Hsu, Y Jung, J Kong, DS Lambrecht, W Liang, C Ochsenfeld, VA Rassolov, LV Slipchenko, JE Subotnik, T Van Voorhis, JM Herbert, AI Krylov, PMW Gill, M Head-Gordon
Molecular Physics
(2014)
113
Choosing RASSCF orbital active spaces for multiple electronic states
F Krausbeck, D Mendive-Tapia, AJW Thom, MJ Bearpark
Computational and Theoretical Chemistry
(2014)
1040
Novel H2 activation by a tris[3,5-bis(trifluoromethyl)phenyl]borane frustrated Lewis pair
TJ Herrington, AJW Thom, AJP White, AE Ashley
Dalton Trans
(2012)
41
Breaking the carbon dimer: The challenges of multiple bond dissociation with full configuration interaction quantum Monte Carlo methods
GH Booth, D Cleland, AJW Thom, A Alavi
Journal of Chemical Physics
(2011)
135
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
Phys Chem Chem Phys
(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
Physical review letters
(2008)
101

Research Group

Research Interest Group

Telephone number

01223 336470

Email address

College