2022

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.

Mar 2022

Norah is one of three scientists featured in a Columbia video highlighting women in STEM! Read her interview to learn more about Norah, the actor and theoretical quantum physicist.

Feb 2022

Our recent JACS paper with the Awschalom and Freedman groups, featuring Arai, Tami, and Sam, is described in an ANL press release: A new platform for customizable quantum devices.

Feb 2022

Hong-Zhou's paper Correlation-consistent Gaussian basis sets for solids made simple is published in J. Chem. Theory Comput.!

Jan 2022

Describing a new QMC method for excited states, applicable to active spaces with up to 100 orbitals, Sam and James's paper Full Configuration Interaction Excited-State Energies in Large Active Spaces from Randomized Subspace Iteration is posted to the arXiv.

2021

Dec 2021

An important step towards making correlated calculations for solids as reliably predictive as those for molecules, Hong-Zhou's paper Correlation-consistent Gaussian basis sets for solids made simple is posted to the arXiv. We're happy to share the alpha version of our GTH basis sets while our manuscript is under review—just ask!

Nov 2021

Norah and Xiao's paper Linear free energy relationships in electrostatic catalysis is posted to the arXiv. This work is part of the Columbia NSF CCI for Chemistry with Electric Fields.

Nov 2021

A great collaboration with the Awschalom and Freedman groups, with theory contributions from Arai, Tami, and Sam, Tunable Cr4+ Molecular Color Centers is published in JACS. Update: And featured on the cover!

Nov 2021

Welcome to Yu Hsuan (Jason) Liang, who joins the group as a first-year PhD student! Before coming to Columbia, Jason received his BS in Chemistry at UC Berkeley, where he performed research in the Head-Gordon group.

Oct 2021

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.

Jun 2021

Welcome to LaToya Anderson (Brooklyn College) and Ellie Mackintosh (Davidson College) who join the group as CCQ summer interns!

Jun 2021

May 2021

A little bit of third-order perturbation theory goes a long way. Malte's paper Improving MP2 band gaps with low-scaling approximations to EOM-CCSD is posted to the arXiv.

May 2021

Malte successfully defends his thesis, "Wave function-based electronic structure theory for solids." Congratulations Dr. Lange!

May 2021

May 2021

Sam is selected as an awardee of the DOE Office of Science Graduate Student Research (SCGSR) program, which will take him to Berkeley Lab for the final year of his PhD!

Apr 2021

Hong-Zhou's paper Fast periodic Gaussian density fitting by range separation is published in J. Chem. Phys., demonstrating a 10x speedup over previous implementations.

Mar 2021

Sam's paper Approximating matrix eigenvalues by randomized subspace iteration is posted to the arXiv. It presents a general approach that we use to design a projector Monte Carlo method for excited states.

Mar 2021

Congratulations to Yeongsu for receiving the Spring 2021 ACS COMP Chemical Computing Group Excellence Award!

Mar 2021

Rescuing MP2 theory for periodic metals, James and Malte's paper Dynamical correlation energy of metals in large basis sets from downfolding and composite approaches is posted to the arXiv!

Feb 2021

Tim will teach Electronic Structure Theory at the 2021 Telluride School on Theoretical Chemistry, to be held virtually July 19-23. More information and a link to apply can be found here.

Feb 2021

Jonathan's paper Vibrational heat-bath configuration interaction is published in J. Chem. Phys.!

Feb 2021

Hong-Zhou's paper Fast periodic Gaussian density fitting by range separation is posted to the arXiv!

Jan 2021

Sylvia's paper Full-frequency GW without frequency is published in J. Chem. Phys.!

Jan 2021

The first of the new year: Bryan's paper Regional Embedding Enables High-Level Quantum Chemistry for Surface Science, a collaboration with Gerald Knizia, is published in J. Phys. Chem. Lett. and featured on the cover!

2020

Dec 2020

A great collaboration with the Nuckolls and Roy groups at Columbia featuring topological band structure characterization by Yeongsu, Polytypism, Anisotropic Transport, and Weyl Nodes in the van der Waals Metal TaFeTe4 is published in JACS!

Nov 2020

Welcome to Ethan Vo, who joins the group as a first-year graduate student! Before coming to Columbia, Ethan was an undergraduate at the University of Washington.

Oct 2020

A new paper from Jonathan is posted to the arXiv! Vibrational heat-bath configuration interaction can efficiently calculate anharmonic vibrational spectra of large molecules with sub-wavenumber accuracy.

Oct 2020

Yeongsu and Sam team-up, comparing large variational calculations and diffusion Monte Carlo for Simulations of Trions and Biexcitons in Layered Hybrid Organic-Inorganic Lead Halide Perovskites!

Oct 2020

Bryan's paper, Regional Embedding Enables High-Level Quantum Chemistry for Surface Science, a collaboration with Gerald Knizia, is posted to the arXiv!

Sep 2020

Sylvia's paper, Full-Frequency GW without Frequency, is posted to the arXiv!

Sep 2020

Welcome back to postdoc James Smith (Ph.D. CU Boulder, Sharma group), who returns to CCQ as a Flatiron Research Fellow after spending summer 2019 as a CCQ Summer Intern.

Sep 2020

Welcome to our new Columbia postdocs Norah Hoffmann (Ph.D. MPSD, Rubio group), Arai Kairalapova (Ph.D. Pitt, Jordan group), Verena Neufeld (Ph.D. Cambridge, Thom group), and Hongzhou Ye (Ph.D. MIT, Van Voorhis group)!

Aug 2020

Malte's paper, Active space approaches combining coupled-cluster and perturbation theory for ground states and excited states, is published in a special issue of Molecular Physics in honor of Jürgen Gauss.

Aug 2020

Tim receives the 2020 ACS National Fresenius Award sponsored by Phi Lambda Upsilon!

Aug 2020

Sam's paper, Improved Fast Randomized Iteration Approach to Full Configuration Interaction, is published in J. Chem. Theory Comput.

Aug 2020

An NSF award to the Berkelbach, Nuckolls, Rovis, Roy, and Venkataraman groups will support the Center for Chemistry with Electric Fields (ChEF), an NSF Center for Chemical Innovation. [Columbia News]

May 2020

Congratulations to Yeongsu for receiving the Columbia Chemistry department's 2020-2021 Kathy Chen Fellowship, which is awarded to a rising fifth year student in recognition of that student's distinguished achievements and potential!

May 2020

Sam's paper, Improved Fast Randomized Iteration Approach to Full Configuration Interaction, with Rob Webber and Jonathan Weare, is posted to the arXiv.

Apr 2020

Mar 2020

Excitons in Solids from Periodic Equation-of-Motion Coupled-Cluster Theory is published in J. Chem. Theory Comput. Congrats Xiao and great work!

Feb 2020

Tim is appointed to the Early Career Editorial Advisory Board of the Journal of Chemical Physics.

Feb 2020

Alan's paper, Ab Initio Linear and Pump-Probe Spectroscopy of Excitons in Molecular Crystals, is published in J. Phys. Chem. Letters! Awesome work Alan!

Feb 2020

Summarizing the design philosophy, features, and impact, Recent developments in the PySCF program package is posted to the arXiv. This article describes the state of PySCF v1.7.1, the final version before v2.0 - coming soon!

Jan 2020

Xiao's paper, Excitons in solids from periodic equation-of-motion coupled-cluster theory, is posted to the arXiv. Across eight semiconductors and insulators, EOM-CCSD predicts first excitation energies with a mean absolute error of 0.27 eV!

Jan 2020

Tim and Michael Thoss served as Guest Editors for a Special Topic on the dynamics of open quantum systems in the Journal of Chemical Physics. Read the preface here.

Jan 2020

Sam is selected as a MolSSI Investment Software Fellow. Congrats Sam!

2019

Oct 2019

Welcome to Sylvia Bintrim (B.S. Penn State) and Petra Shih (B.S., M.S. National Taiwan University), who join the group as first-year Ph.D. students!

Oct 2019

Holstein or Peierls? Why choose? Jonathan's paper with Denis Golez from CCQ, A unification of the Holstein polaron and dynamic disorder pictures of charge transport in organic semiconductors, is posted to the arXiv.

Sep 2019

Welcome to Giulia Biffi, a visiting Ph.D. student from Roman Krahne's group at the Italian Institute of Technology!

Sep 2019

Yeongsu's work, Optical Properties of Layered Hybrid Organic-Inorganic Halide Perovskites: A Tight-Binding GW-BSE Study, is published in J. Phys. Chem. Letters — an accurate but efficient approach for band gaps and excitons in complex, heterogeneous materials with large unit cells!

Sep 2019

Alan's paper, Ab Initio Linear and Pump-Probe Spectroscopy of Excitons in Molecular Crystals, is posted to the arXiv — the first application of atomistic periodic EE-EOM-CCSD!

Sep 2019

A great collaboration with the Weiss (Northwestern) and Darancet (ANL) groups, Large Band Edge Tunability in Colloidal Nanoplatelets, is published in Nano Letters.

Sep 2019

Welcome to our newest Columbia postdoc, Tamar Goldzak! Tami previously completed her Ph.D. with Nimrod Moiseyev at the Technion and was a postdoc with Troy Van Voorhis at MIT.

Aug 2019

A great collaboration featuring Yeongsu's theory, Dielectric disorder in two-dimensional materials is published in Nature Nanotechnology.

Aug 2019

Jul 2019

Tim receives the Presidential Early Career Award for Scientists and Engineers (PECASE). Thank you to the AFOSR for the nomination and for supporting our research! [Columbia Science News]

Jul 2019

Tim is named the winner of the 2019 Hermann Kuemmel Early Achievement Award in Many-Body Physics, "for making possible the determination of condensed phase spectra within the framework of coupled cluster theory, and for elucidating the relationship between excited-state coupled cluster theory and Green’s function diagrammatic approximations." Honored to have our work on coupled cluster recognized by an award named for one of its pioneers!

Jun 2019

Congratulations to Sam, who was selected as a 2019 MolSSI Seed Software Fellow!

May 2019

Welcome to our summer researchers, Sylvia Bintrim and James Smith! Sylvia is an incoming PhD student at Columbia and an NSF Graduate Research Fellow. James is a summer intern at CCQ, visiting from CU Boulder, where he is a PhD student in the Sharma group.

May 2019

A collaboration long in the making: Coupled-cluster impurity solvers for dynamical mean-field theory is posted to the arXiv.

May 2019

Sam's paper, with Rob Webber and Jonathan Weare of NYU, Beyond Walkers in Stochastic Quantum Chemistry: Reducing Error using Fast Randomized Iteration, is posted to the arXiv - the group's first foray into QMC!

Apr 2019

Congratulations to James for being selected to receive a 2019 NSF Graduate Research Fellowship! UPDATE: And the National Defense Science and Engineering Graduate Fellowship (NDSEG)! Tough choice.

Mar 2019

Happy International Women's Day! Here's Yeongsu presenting her work on excitons in Ruddlesden-Popper perovskites at the APS March Meeting. According to IPEDS and the APS, only 40% of PhDs in chemistry and 20% of PhDs in physics are earned by women. Many resources available from the ACS Women Chemists Committee, the APS Women in Physics initiative, and the APS STEP UP 4 Women program.

Mar 2019

Honored to receive the NSF CAREER Award. Thank you to the NSF's Chemical Theory, Models and Computation Methods and Condensed Matter and Materials Theory programs for supporting our research and education efforts!

Mar 2019

At the APS March meeting, kicking off our Focus Session, "Periodic quantum chemistry beyond DFT," co-organized with Garnet Chan. Sessions include "DFT, embedding, and beyond," "Quantum Monte Carlo," and "Wavefunction methods."

Feb 2019

The PySCF paper was one of the ten most downloaded articles in the past year in WIREs Computational Molecular Science.

Jan 2019

Xiao Wang joins CCQ as a Flatiron Research Fellow. Previously, Xiao received his Ph.D. with Fritz Schaefer at the University of Georgia and was a postdoc with Ed Valeev at Virginia Tech. Welcome Xiao!

Jan 2019

Random-phase approximation excitation energies from approximate equation-of-motion coupled-cluster doubles is selected for the 2018 JCP Editors' Choice, "a few of the many notable JCP articles of 2018 that present significant and definitive research in experimental and theoretical areas of the field."

Jan 2019

The group is moving to New York City! Tim has accepted a joint position in the Department of Chemistry at Columbia University and the newly-established Center for Computational Quantum Physics at the Flatiron Institute, a division of the Simons Foundation.

2018

Oct 2018

Alan's second paper in as many weeks - this time, plasmon excitations in metals from equation-of-motion coupled-cluster theory. Ab Initio Lifetime and Concomitant Double-Excitation Character of Plasmons at Metallic Densities is posted to the arXiv.

Sep 2018

Combining wavefunction-based quantum chemistry with Green's function techniques: Alan's paper, Vertex corrections to the polarizability do not improve the GW approximation for molecules, is posted to the arXiv.

Jul 2018

Tim's paper, Random-phase approximation excitation energies from approximate equation-of-motion coupled-cluster doubles, is published as a Communication in J. Chem. Phys. and selected as an Editor's Pick.

Jul 2018

Jul 2018

Really going to miss having this guy in the group. Good luck at Caltech, Shi-Ning!

May 2018

Shi-Ning presents his undergraduate thesis, "Classical and quantum theories for screened Coulomb interactions" and is chosen to receive the Norman H. Nachtrieb Memorial Award for Excellence in Undergraduate Studies in Chemistry. Congrats Shi-Ning!

May 2018

Congratulations to Sam, maybe the first theoretical chemistry student to win the Gerhard Closs Teaching Award in Organic Chemistry!

May 2018

Malte's paper, On the Relation Between Equation-of-Motion Coupled-Cluster Theory and the GW Approximation, appears on the arXiv. They're not as different as you may think! IP/EA-EOM-CCSD contains (most of) the physics described by the GW approximation, but many additional effects that improve the accuracy.

Apr 2018

Congratulations to Jonathan and Malte, who have been selected as 2018 NSF Graduate Research Fellows!

Feb 2018

Many thanks to the students of BU, MIT, and Harvard, who hosted Tim for the Greater Boston Area Theoretical Chemistry Lecture Series and three exciting days of scientific discussions.

Feb 2018

Very honored to be named a 2018 Sloan Research Fellow. Thank you to the Sloan Foundation for supporting our research! [UChicago News, NY Times Ad]

Jan 2018

Yeongsu's paper, Environmentally sensitive theory of electronic and optical transitions in atomically thin semiconductors, is published as a Rapid Communication in Phys. Rev. B, and selected as an Editors' Suggestion!

Jan 2018

Congratulations to Yeongsu, Jonathan, and Malte, who have all passed their second-year candidacy exams!

2017

Dec 2017

Jonathan's paper, Linear and nonlinear spectroscopy from quantum master equations, is published in J. Chem. Phys.

Dec 2017

Two new graduate students join the group! Welcome to Sam Greene (B.S. UChicago, M.Sc. Oxford), who will be jointly advised by Jonathan Weare (UChicago Statistics), and James Callahan (B.A. Harvard).

Oct 2017

Tim is selected for the US Air Force Young Investigator Program (YIP), which will fund our work on exciton interactions in semiconductor nanostructures. The objective of the Air Force YIP is "to foster creative basic research in science and engineering, enhance early career development of outstanding young investigators, and increase opportunities for the young investigators to recognize the Air Force mission and the related challenges in science and engineering."

Sep 2017

Alan Lewis (D. Phil. Oxford University) joins the group as a postdoctoral researcher. Welcome, Alan!

Sep 2017

Quantum master equations: time-tested classics for single-time observables, but how good are they for multi-time correlation functions, like the ones probed in spectroscopy? Read Jonathan's paper, Linear and nonlinear spectroscopy from quantum master equations, to find out!

Sep 2017

Can we use atomically-thin semiconductors as optical sensors of the local chemical environment? Read Yeongsu's paper, Environmentally-Sensitive Theory of Electronic and Optical Transitions in Atomically-Thin Semiconductors, to find out why it's harder than you think!

Jul 2017

Farewell to pseudopotentials! Gaussian and plane-wave mixed density fitting for periodic systems has been posted to the arXiv.

Jul 2017

We have received a Start-Up Research Grant from the US-Israel Binational Science Foundation to study the role of low-frequency nuclear fluctuations in soft semiconductors in collaboration with Omer Yaffe's group at the Weizmann Institute!

Jun 2017

Shi-Ning leaves us for the summer, to participate in the Amgen Scholars Program at Kyoto University, where he will work in the research group of Prof. Yoshitaka Tanimura. Good luck Shi-Ning!

Jun 2017

Many thanks to Ben Levine and the other organizers at MSU for hosting the excellent 49th Midwest Theoretical Chemistry Conference. We are excited to announce that the 50th MWTCC will be held in Summer 2018 at the University of Chicago. More details can be found at mwtcc.uchicago.edu

May 2017

Bryan Lau (Ph.D. Northwestern University) joins the group as a postdoctoral researcher. Welcome, Bryan!

May 2017

Malte receives the Nathan Sugarman Teaching Award in General Chemistry!

May 2017

Tim heads to Europe to speak at the Theory Department of the Fritz Haber Institute in Berlin and the CECAM Workshop Theoretical Chemistry for Extended Systems in Toulouse.

Apr 2017

University of Chicago undergraduate Shi-Ning Sun joins the group!

Mar 2017

Tim visits nearby Northwestern and gives a talk at the Northwestern-Argonne Solar Energy Research Center (ANSER).

Mar 2017

Tim and Greg Scholes organize a Focus session on Spectroscopy and Dynamics of Multichromophore Systems at APS March Meeting.

Feb 2017

Gaussian-Based Coupled-Cluster Theory for the Ground State and Band Structure of Solids has been accepted for publication in the Journal of Chemical Theory and Computation.

Jan 2017

We contribute to the open-source PySCF software package, especially concerning excited-state and condensed-phase electronic structure. A preprint describing the capabilities and design philosophy of PySCF has been posted to the arXiv: The Python-based Simulations of Chemistry Framework (PySCF).

Jan 2017

Tim gives an invited talk at the 18th Total Energy and Force Methods workshop, held at ICTP.