Recent news

Sep 2021

Yeongsu and Sylvia's paper A simplified GW/BSE approach for charged and neutral excitation energies of large molecules and nanomaterials is posted to the arXiv! Exhausted with building semiempirical models by hand (like in this paper), we have long wanted a cheap, black-box method.

Aug 2021

Petra's paper Anharmonic Lattice Dynamics from Vibrational Dynamical Mean-Field Theory is posted to the arXiv! A new embedding approach for interacting phonons, VDMFT is exact in the harmonic and molecular limits, nonperturbative, systematically improvable, and applicable to classical or quantum nuclei.

Aug 2021

Congratulations to Tami, who has accepted a faculty position in the Materials Science and Engineering program at Bar-Ilan University, where she will start in January 2022!

Aug 2021

Malte's paper Improving MP2 band gaps with low-scaling approximations to EOM-CCSD is published in J. Chem. Phys. and selected as an Editor's Pick.

Jul 2021

One week, two new doctors! Yeongsu defends her thesis "Semiempirical methods for excited states of nanomaterials" and Jonathan defends his thesis "Dynamics and spectroscopy of strongly coupled electrons and nuclei". Congratulations Dr. Cho and Dr. Fetherolf!

Jul 2021

Hong-Zhou's paper Tight distance-dependent estimators for screening two-center and three-center short-range Coulomb integrals over Gaussian basis functions is posted to the arXiv. The results in the paper are general but were needed by us to bring increased speed and robustness to our periodic range-separated Gaussian density fitting.

Jul 2021

Because there's so much more to life beyond the first excited state, Xiao's paper Absorption Spectra of Solids from Periodic Equation-of-Motion Coupled-Cluster Theory is posted to the arXiv.

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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)


Tamar Goldzak

Postdoctoral Researcher

Postdoc MIT (2017-2019)
Ph.D. Technion (2017)
B.Sc. Technion (2010)


Sam Greene

Graduate Student

DOE SCGSR Fellow (2021-2022)
MolSSI Software Fellow (2019-2021)
M.S. Oxford University (2016)
Rhodes Scholar (2014-2016)
B.S. University of Chicago (2014)


Norah Hoffmann

Postdoctoral Researcher

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)


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

Ph.D. student, IIT, Krahne group

Yeongsu Cho

Graduate student

Postdoc, MIT, Kulik group

Jonathan Fetherolf

Graduate student

Postdoc, Yale, Hammes-Schiffer group

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. He currently serves on the Early Career Editorial Advisory Board for the Journal of Chemical Physics.

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.