Recent news

Jun 2022

Norah and Xiao's paper Linear Free Energy Relationships in Electrostatic Catalysis is published in ACS Catalysis.

Jun 2022

Congratulations to Sam, who is selected as a 2022 Schmidt Science Fellow, which will support his postdoctoral work in computational materials science for renewable energy applications! Good luck Sam, we'll miss you!

Jun 2022

Tim receives the DOE Early Career Award, which will fund our work on the vibrational dynamics of strongly anharmonic materials.

Jun 2022

James successfully defends his thesis "Applications of Coupled Cluster Theory to Models of Extended Systems of Fermions". Congratulations Dr. Callahan!

Jun 2022

Sylvia and Hong-Zhou's paper Integral-direct Hartree-Fock and Møller-Plesset Perturbation Theory for Periodic Systems with Density Fitting: Application to the Benzene Crystal is posted to the arXiv. This development eliminates formerly prohibitive storage bottlenecks for calculations on materials with large unit cells in high-quality basis sets.

Jun 2022

Sam successfully defends his thesis "Stochastic Electronic Structure Methods for Molecules and Crystalline Solids". Congratulations Dr. Greene!

May 2022

Jonathan and Petra's paper Conductivity of an electron coupled to anharmonic phonons is posted to the arXiv. We use mixed quantum-classical Ehrenfest dynamics to study the impact of anharmonicity and to evaluate several simpler theories.

May 2022

James's paper The normal state of attractive Fermi gases from coupled-cluster theory, in collaboration with John Sous, is posted to the arXiv. In a new direction for the group, we demonstrate the successes, struggles, and promise of CC theory for this form of interacting quantum matter.

May 2022

Congratulations to Sam, who is awarded the Chemistry Department's Pegram Award, given to graduate students in their final year, in recognition of meritorious achievements in chemical research!

May 2022

Yeongsu and Sylvia's paper Simplified GW/BSE Approach for Charged and Neutral Excitation Energies of Large Molecules and Nanomaterials is published in J. Chem. Theory Comput.! Update: And featured on the cover!

May 2022

Tim is promoted to Associate Professor of Chemistry with tenure, effective July 1, 2022. Since the start of our group in 2016, it's been a wild and unpredictable six years. This milestone would never have been possible without incredible students, postdocs, and colleagues at the University of Chicago, Columbia, and the Flatiron Institute. 🙏

Apr 2022

Congratulations to Xiao, who will be starting in July 2022 as an Assistant Professor in the Department of Chemistry & Biochemistry at UC Santa Cruz!

Apr 2022

Verena and Hong-Zhou's paper Ground-state properties of metallic solids from ab initio coupled-cluster theory is posted to the arXiv. We evaluate the performance of CCSD and some extensions for solid lithium and aluminum—quite a challenge for wavefunction-based quantum chemistry! This work is part of the Columbia Center for Computational Electrochemistry.

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Group Members


Timothy Berkelbach

Principal Investigator

Fellow at PCTS (2014-2016)
Ph.D. Columbia University (2014)
B.A. NYU (2009)


Sylvia Bintrim

Graduate Student

NSF Graduate Research Fellow (2019-2022)
B.S. Penn State (2019)


James Callahan

Graduate Student

NDSEG Fellow (2019-2022)
M.S. University of Chicago (2018)
B.A. Harvard University (2014)


Norah Hoffmann

Leopoldina Postdoctoral Fellow

Ph.D. Max Planck Institute, Hamburg (2020)
M.Sc. Berlin Institute of Technology & FHI (2016)
B.Sc. Berlin Institute of Technology (2013)


Arailym Kairalapova

Postdoctoral Researcher

Ph.D. University of Pittsburgh (2020)
B.S. Nazarbayev University (2015)


Bryan Lau

Postdoctoral Researcher

Postdoc Flatiron Institute (2019-2020)
Postdoc University of Chicago (2017-2019)
Ph.D. Northwestern University (2017)
B.S. University of Toronto (2011)


Yu Hsuan (Jason) Liang

Graduate Student

B.S. UC Berkeley (2021)


Verena Neufeld

Postdoctoral Researcher

Ph.D. University of Cambridge (2020)
M.Phil. University of Cambridge (2015)
M.Sci., B.A. University of Cambridge (2014)


Petra Shih

Graduate Student

M.S. National Taiwan University (2018)
B.S. National Taiwan University (2016)

James Smith

James Smith

Flatiron Research Fellow

Ph.D. University of Colorado Boulder (2020)
B.S. Davidson College (2014)


Ethan Vo

Graduate Student

B.S. University of Washington (2020)


Xiao Wang

Flatiron Research Fellow

Postdoc Virginia Tech (2016-2018)
Ph.D. University of Georgia (2016)
B.S. Beihang University (2012)


Hong-Zhou Ye

Postdoctoral Researcher

Ph.D. MIT (2020)
B.S. Peking University (2015)

Show/hide former members

LaToya Anderson

Visiting undergraduate student

B.S. Brooklyn College (expected 2024)

Giulia Biffi

Visiting graduate student

Postdoc, Centro de Fisica de Materiales, Coto group

Yeongsu Cho

Graduate student

Postdoc, MIT, Kulik group

Jonathan Fetherolf

Graduate student

Postdoc, Yale, Hammes-Schiffer group

Tamar Goldzak

Postdoctoral Researcher

Assistant Professor, Bar-Ilan University

Sam Greene

Graduate Student

Postdoc, UT Austin, Siegel group, starting Aug 2022

Malte Lange

Graduate Student

CEO/CTO, Nomfe

Alan Lewis

Postdoctoral Researcher

Postdoc, MPSD, Rossi group

Ellie Mackintosh

Visiting undergraduate student

Ed.M. student, Harvard (expected 2022)

Shi-Ning Sun

Undergraduate Student

Ph.D. student, Caltech, Minnich group

Research areas

We work on a variety of quantum-mechanical problems motivated by excited-state phenomena. This research occurs at the fascinating interface of physical chemistry, condensed-matter physics, and materials science.

Quantum dynamics and spectroscopy

Building on modern theories of quantum dynamics, we develop powerful simulation techniques for nonequilibrium and time-resolved spectroscopies. These new tools enable the accurate simulation of extremely large and complex sytems, providing new insights into excited-state structure and dynamics.

Emerging materials

We are actively exploring the excited-state behavior of fundamentally interesting and technologically promising materials, especially those that are anisotropic, layered, or low-dimensional. Particular materials of interest include conjugated polymers, organic molecular crystals, and quasi-two-dimensional inorganic semiconductors.

Condensed-phase electronic structure

Aiming towards highly accurate but insightful descriptions of electronic excitations, we formulate and apply electronic structure methods adapted for the condensed phase. Some of our favorite tools are low-energy effective theories, many-body diagrammatics, and coupled-cluster techniques.

Interested in learning more?

Check out our publications!

About Tim

Timothy Berkelbach is an Associate Professor in the Department of Chemistry at Columbia University and a Research Scientist in the Center for Computational Quantum Physics at the Flatiron Institute. From 2016 to 2018, he was a Neubauer Family Assistant Professor in the Department of Chemistry and the James Franck Institute at the University of Chicago. He received his B.A. in physics and chemistry from NYU in 2009 and his Ph.D. in chemical physics from Columbia University in 2014, where he was a Department of Energy Office of Science Graduate Research Fellow advised by David Reichman. Tim then spent two years as a fellow of the Princeton Center for Theoretical Science, working with Garnet Chan. From 2019-2021, he served on the Early Career Editorial Advisory Board for the Journal of Chemical Physics. Since 2019, he has been the co-chair of Columbia Chemistry's Committee for Inclusion, Equity, and Diversity.

Columbia University

3000 Broadway, 518 Havemeyer Hall, New York NY 10027

1 212 854 0347

Flatiron Institute

162 Fifth Avenue, Office 934, New York NY 10010

1 646 876 5930

Join us!

We welcome students and postdocs of all genders, races, ages, sexual orientations, and disability statuses. If you're interested in joining us in one of the most multicultural cities in the world, contact Tim for more information on the graduate program at Columbia or postdoctoral openings at Columbia or the Flatiron Institute.