Professor Alex Thom

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

Linked coupled cluster Monte Carlo.

RST Franklin, JS Spencer, A Zoccante, AJW Thom

The Journal of Chemical Physics

(2016)

144

044111

(doi: 10.1063/1.4940317)

Holomorphic Hartree-Fock Theory: An Inherently Multireference Approach

HGA Burton, AJW Thom

J Chem Theory Comput

(2015)

167

(doi: 10.1021/acs.jctc.5b01005)

EXTRA: Towards an efficient open platform for reconfigurable High Performance Computing

CB Ciobanu, AL Varbanescu, D Pnevmatikatos, G Charitopoulos, X Niu, W Luk, MD Santambrogio, D Sciuto, M Al Kadi, M Huebner, T Becker, G Gaydadjievll, A Brokalakis, A Nikitakis, AJW Thom, E Vansteenkiste, D Stroobandt

2015 IEEE 18th International Conference on Computational Science and Engineering

(2015)

339

(doi: 10.1109/cse.2015.54)

Minimising biases in full configuration interaction quantum Monte Carlo.

WA Vigor, JS Spencer, MJ Bearpark, AJW Thom

Journal of Chemical Physics

(2015)

142

104101

(doi: 10.1063/1.4913644)

Open-Source Development Experiences in Scientific Software: The HANDE Quantum Monte Carlo Project

JS Spencer, NS Blunt, WA Vigor, FD Malone, WMC Foulkes, JJ Shepherd, AJW Thom

Journal of Open Research Software

(2015)

(doi: 10.5334/jors.bw)

Holomorphic Hartree–Fock Theory and Configuration Interaction

HG Hiscock, AJW Thom

Journal of chemical theory and computation

(2014)

4795

(doi: 10.1021/ct5007696)

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

184

(doi: 10.1080/00268976.2014.952696)

Choosing RASSCF orbital active spaces for multiple electronic states

F Krausbeck, D Mendive-Tapia, AJW Thom, MJ Bearpark

Computational and Theoretical Chemistry

(2014)

1040-1041

(doi: 10.1016/j.comptc.2014.03.030)

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)

9019

(doi: 10.1039/c2dt30384a)

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

084104

(doi: 10.1063/1.3624383)

Professor Alex Thom

University Lecturer

PhD and MPhil Positions

Dr Thom discusses his research

Publications

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Email address

College

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