Presentations
Laura Gagliardi (University of Chicago)
Learning Multireference Chemistry: Accurate Models for Excited States and Dynamics
Multireference electronic structure methods are essential for describing chemistry in which a single electronic configuration is not enough: bond breaking, transition-metal reactivity, and excited-state processes are prominent examples. Yet their routine use in complex chemical environments remains limited by computational cost, by the need for robust active-space choices, and by the difficulty of following electronic structure consistently along reaction pathways.
I will discuss recent progress from our group toward making multireference methods more practical, systematic, and transferable. The first example concerns methane C–H activation at metal–oxo sites in metal–organic framework nodes. We have introduced an automated multireference workflow in which the active space is localized on the chemically relevant fragment. This strategy provides a route to applying multireference methods to realistic catalytic environments and to analyzing, across different metal centers, how metal–oxygen bonding, radical character, and electronic structure control reactivity.1
The same need for consistency also arises when multireference data are used to train machine learning models. To address this challenge, we developed machine learning potentials trained on multireference electronic structure data together with the weighted active space protocol, which maintains consistent active-space assignments across diverse nuclear geometries. Combined with active learning and enhanced sampling, this approach enables data-efficient molecular dynamics with multireference accuracy. We applied it to TiC+-catalyzed methane C–H activation, a reaction for which conventional density functional theory struggles because of strong multiconfigurational character.2
[1] J. Wardzala, Y. Kim, R. Khurana, M. Mandal, M. Delferro, C. Liu, L Gagliardi From Oxo to Oxyl to Biradical: Systematic Multireference Calculations of Methane Activation at MOF Nodes, J. Am. Chem. Soc. 2026, 148, 27411–27420. DOI: https://doi.org/10.1021/jacs.6c05408
[2] A. Seal, S. Perego, M. R. Hennefarth, U. Raucci, L. Bonati, A. L. Ferguson, M. Parrinello, and L. Gagliardi, Weighted Active Space Protocol for Multireference Machine-Learned Potentials, PNAS, 2025, 122, e2513693122. DOI: 10.1073/pnas.2513693122
About: Laura Gagliardi is the Richard and Kathy Leventhal Professor of Chemistry and Molecular Engineering at the University of Chicago. She earned her PhD in Theoretical Chemistry from the University of Bologna before doing postdoctoral research at Cambridge. Her research develops quantum chemical methods and applies them to catalysis, photochemistry, spectroscopy, and energy-related molecular and materials systems.
Anna I. Krylov (University of Southern California)
Chirality, Spin, and Breaking Symmetry Between Enantiomers: A Quantum Chemistry Perspective
Two fundamental questions have puzzled scientists for more than 150 years. "How did life become homochiral?" and "why was this specific handedness selected?" Recently, it has been shown that homochirality could have emerged through the enantioselective interactions of molecules with magnetic substrates due to the asymmetric crystallization of an RNA precursor on a magnetite substrate, abundant on early Earth. This phenomenon is based on the chirality- induced spin selectivity (CISS) effect. This lecture will discuss fundamental ingredients of CISS effect and illustrate how spin-involving processes can have different outcomes in the two enantiomers of chiral molecules.
Y. Paltiel, D. Goldberg, N. Yuran, S. Yochelis, J.H. Soh, C. Seibel, J. Gauss, S. Zilberg, S.F. Ozturk, J. Fransson, A.I. Krylov, and R. Naaman; Dynamic breaking of mirror symmetry in spin-dependent electron transport through chiral media causes enantiomeric excesses
Science Advances 12, eaec9325 (2026).
About: Anna Krylov is USC Associates Chair in Natural Sciences and Professor of Chemistry at the University of Southern California. Working in theoretical and computational quantum chemistry, she is known for her development of robust black-box methods to describe complicated multi-configurational wave functions in single-reference formalisms, such as the coupled-cluster and equation-of-motion approaches.
Sho Takatori (Stanford University)
Many-Body Hydrodynamic Interactions in Complex Fluids
Colloidal interactions in complex systems are often mediated by a dynamic surrounding bath that is viscoelastic, active, and far from equilibrium. I describe how we use quantitative microscopy, optical control, and theory to study the transmission of fluid-mediated forces between colloids embedded within complex fluids. Our goal is to develop constitutive models that bridge microscopic dynamics and continuum transport, with insight into kernels that encode spatiotemporal nonlocality and nonlinearities.
About: Sho Takatori is Associate Professor in Chemical Engineering at Stanford University. Sho began his lab at UC Santa Barbara in 2020 and moved to Stanford in 2025. He has received the Packard fellowship, DARPA Young Faculty Award, and NSF CAREER. Sho is passionate about public speaking, science education, and technical communication.
Michael A. Webb (Princeton University)
Simple Explanations for Complex Things: From Static Electricity to Stimuli-response in Soft Matter
Complex soft matter phenomena often appear to demand complex explanations. Yet, substantial insight can emerge from asking whether the right physical picture has been identified. In this talk, I will discuss two examples from our recent work where minimal thermodynamic and theoretical frameworks help rationalize seemingly intricate behavior.
The first concerns contact charging, or static electricity, in which materials acquire charge after contact and separation. Although familiar from everyday experience and important in technologies ranging from printing to particle handling, its molecular origins remain difficult to predict, particularly for insulating materials, where even the identity of the charge carrier remains uncertain. I will describe how the direction of charge transfer between polymer surfaces can be understood by comparing the interfacial thermodynamics of water ions and how this is influenced by nanoscale hydrophobicity. This perspective provides a simple molecular explanation for why different materials tend to charge positively or negatively.
The second example concerns stimuli-responsive polymer solutions, whose phase behavior can change dramatically with temperature, solvent composition, or other environmental conditions. Such behavior motivates applications in sensing, separations, and adaptive materials, but its mechanistic origins can be surprisingly unclear. I will describe how these effects can be captured using a lattice framework that combines Flory-Huggins solution theory with Potts-like internal states through a well-defined Hamiltonian, without ad hoc temperature-dependent parameters. Subsequent analysis will reveal pathways of phenomena like heating-induced coil-globule transitions.
Together, these examples illustrate how simple models, grounded in molecular physics, can organize puzzling phenomena and suggest new ways to predict and design soft materials behavior.
About: Michael Webb is Assistant Professor in the CBE department at Princeton, where he researches simulation and machine learning of soft materials. Before joining Princeton in 2020, he obtained his BS from UC Berkeley and PhD from Caltech, and performed postdoctoral study at the University of Chicago/Argonne. He has been recognized with awards from the ACS, NSF, and MRS.
Jianzhong Wu (University of California, Riverside)
Multiscale Modeling of Double Layer Effects in Electrocatalysis
Electrocatalytic reactions are central to advancing sustainable energy technologies and mitigating environmental impacts, particularly in renewable energy conversion and greenhouse gas reduction. Yet, the intricate structure of the electric double layer (EDL) poses significant challenges to understanding how electrolytes influence reaction mechanisms at electrified interfaces. In this talk, I will discuss a theoretical framework that integrates classical density functional theory (cDFT) for describing the diffuse layer, the Booth model for capturing the field-dependent dielectric behavior of the Stern layer, and Kohn-Sham density functional theory (KS-DFT) for resolving surface reactivity. This unified approach provides a self-consistent description of the interrelationships among electrode potential, surface charge density, interfacial electric field, Stern layer dielectric constant, and capacitance across diverse electrolyte conditions. By bridging atomic-scale surface properties with macroscopic experimental conditions, the multiscale framework offers mechanistic insights into ionic effects on electrocatalytic performance.
About: Jianzhong Wu is Professor in Chemical and Environmental Engineering at UC Riverside. Recognized for his contributions to classical density functional theory, multiscale modeling, and interdisciplinary research, he is an elected Fellow of the American Institute of Chemical Engineers, American Physical Society, and American Institute for Medical and Biological Engineering.
Weitao Yang (Duke University)
From Functional Approximations to Excited State Theory and Computation in DFT
Conventional density functional approximations suffer from significant delocalization errors, leading to underestimating energy gaps in molecules and materials, incorrectly predicting the dissociation limits of chemical bonds, overdelocalizing charge distributions, and misaligning energy levels at interfaces. We have developed the Localized Orbital Scaling Correction (LOSC) to correct the delocalization errors, elevating DFT to a new level of robustness and accuracy, with major improvement in total energy, density and energy levels for finite and periodic systems. The orbital energies derived from LOSC-DFT calculations also provide accurate information about excited states directly from the ground-state calculations. Parallelly in terms of total energies, ∆SCF has been used since the 1970s to achieve impressive accuracy for excited states, but it has lacked formal justification. We have now established the theoretical foundation, demonstrating that a valid functional for excited states requires going beyond electron density alone and using the first-order density matrix of the non-interacting reference system. The minimum of this functional corresponds to the ground state energy, consistent with ground state DFT, while the stationary solutions yield excited-state energies and electron densities, validating the ∆SCF approach. Our work establishes linear conditions for fractional charges in excited states and introduces the concept of excited state chemical potentials, which clarifies the physical meaning of occupied and virtual orbital energies. Building on this ∆SCF foundation, we have formulated novel, highly accurate, and efficient methods for excited state calculations, based on occupancy extrapolation to reach many excited states from ground state calculations, and quasiparticle Hamiltonian to describe multiconfigurational states.
About: Weitao Yang, the Philip Handler Professor of Chemistry at Duke University, is a leading figure in density functional theory (DFT), known for contributions to the B3LYP functional, pioneering linear-scaling methods, and influential concepts including Fukui functions and Noncovalent Interaction (NCI). His research has uncovered systematic DFT deficiencies and guided the development of more accurate theoretical frameworks.
Joel Yuen-Zhou (University of California, San Diego)
Organic Chromophores as Spin-Optical Interfaces: From Quantum Sensing to Photoredox Catalysis
The transduction of quantum information from the microwave to the UV-visible range can be surprisingly robust in open-shell organic molecules. At the heart of this possibility is the observation that small changes in spin dynamics can lead to drastic changes in electronically excited processes. In my talk, I will describe our recent efforts designing organic molecules whose ground-state properties can be exploited for magnetometry, serving as organic analogues of NV centers [1,2,3]; some of the predictions have been demonstrated by recent experiments of the Wasielewski group [4,5]. These examples provide clear evidence that chemical design can serve to augment the toolbox of quantum information. Conversely, I will conclude by suggesting that the opposite should also be true: subtle control of spin dynamics should lead to dramatic changes in chemical behavior in appropriately designed schemes for photoredox catalysis, and in particular, for enantiopurification [6].
References
[1] J. Am. Chem. Soc. 146, 22, 15549 (2024).
[2] ACS Cent. Sci. 11, 1, 116–126 (2025).
[3] J. Am. Chem. Soc. 147, 26, 22529–22541 (2025).
[4] J. Am. Chem. Soc. 146, 40, 27935 (2024).
[5] J. Am. Chem. Soc. 147, 26, 22951–22960 (2025).
[6] J. Am. Chem. Soc. 147, 40, 36579–36588 (2025).
About: Joel Yuen-Zhou, Professor and Kurt and Beatrice Shuler Chair of Theoretical Chemical Physics at UC San Diego, develops theoretical tools and concepts for understanding new light–matter interfaces, including molecular polaritons and organic spins for quantum sensing. He has received Sloan, Camille-Dreyfus, Keck, and Brown awards, and the 2025 Medal of the International Academy of Quantum Molecular Science.