Greater Boston Area Theoretical Chemistry Lecture Series

2016-2017 Speaker Schedule

The biophysics of lipid membranes: elasticity meets geometry and biology

11/02/16 4:15pm

MIT Building 4, Room 163

Markus Deserno

Carnegie Mellon University




Markus Deserno

All living cells have a barrier that separates them from their environment: a thin self-assembled structure called a “lipid bilayer membrane”. Eukaryotic cells also have numerous membraneous structures inside themselves to further compartmentalize distinct organelles, such as the cell nucleus or the endoplasmic reticulum. It turns out that biomembranes play important roles in innumerable cellular processes, and that one key to their functional diversity lies in the remarkable elastic properties which they exhibit: lipid bilayers are molecularly thin two dimensional fluids which resists bending, stretching, and lipid tilting in such a way as to communicate forces and information through elasticity and geometry. In my talk I will discuss some of the fascinating aspects of lipid membrane biophysics, and I will explain in more detail several novel approaches we have developed in my group to probe both the various phenomena and the elastic properties of these amazing structures.

Digging Deep into Reactions with New First Principles Techniques

11/09/16 4:15pm

MIT Building 4, Room 163

Paul Zimmerman

University of Michigan




Paul Zimmerman

Effective sampling of reaction pathways is a longstanding challenge in molecular simulation. Difficulties in this area often result from chemical interactions between the environment and the reactive groups, resulting in a high dimensionality of the reaction pathway. In addition to this well-known issue of sampling environmental degrees of freedom, a second challenge is just as basic: realistic hypotheses of the reaction mechanism are needed, but not always available for systems of emerging interest. In this talk, I will introduce graph-based approaches that can thoroughly evaluate reaction coordinates in order to computationally locate the most kinetically feasible reaction pathways. Complementary advances in the Growing String Method for optimizing reaction paths at low effort will also be discussed. These tools are widely applicable to stoichiometric and catalytic systems that include simple environments and complex, solution-phase reactions. Examples will be provided for reactive systems where solvent was found to play an important role in the reaction. These will include catalysis involving transmetalation reactions for electronic polymer growth, and C-H activation reactions.

Excited States and Energy Conversion in Organic Crystals and at Interfaces via First-Principles Methods

11/16/16 4:15pm

Note the location change:

Harvard University, Mallinckrodt Building, Pfizer Lecture Hall

Jeffrey Neaton

University of California, Berkeley




Jeffrey Neaton

Organic crystals and hybrid interfaces are highly tunable, diverse classes of cheap-to-process materials with promise for next-generation optoelectronics. Further development of new materials requires new intuition that links atomic- and molecular-scale morphology to underlying excited-state properties and phenomena. I will review ab initio methods for calculating excited-state and transport properties of crystalline solids and interfaces, and show several applications, where we have used these methods to explain or drive new experiments. Specifically, I will cover the use of first-principles density functional theory with tuned hybrid functionals, and many-body perturbation theory within the GW approximation and the Bethe-Salpeter equation approach, for computing and understanding spectroscopic properties of acene crystals, including new insights into measured multiexciton phenomena such as singlet fission; as time permits, I will additionally share preliminary results on low-dimensional materials, such as 2d chalcogenides, and halide perovskites. I will also discuss multiple approaches to calculating level alignment at metal-molecule interfaces, where we have recently generalized optimally-tuned range-separated hybrid functionals to treat the electronic structure with accuracy comparable to many-body perturbation theory, and describe implications for single-molecule junction transport measurements.

Insights into the structure and dynamics of biomolecules in cellular environments from computer simulations

11/30/16 4:15pm

MIT Building 4, Room 163

Michael Feig

Michigan State University




Michael Feig

Biological macromolecules such as proteins and nucleic acids have become well-understood at the single molecule level but it is much less clear how the structure-dynamics-function paradigms established largely under dilute and homogeneous conditions hold up under realistic biological conditions where crowding, heterogeneity, and the presence of a diverse set of metabolites are important factors. Using computational approaches we are exploring model systems of dense crowded systems ranging from simple spherical crowder models to concentrated protein solutions and a comprehensive model of a bacterial cytoplasm with all of the key components present in full atomistic detail. Simulations of these systems show altered dynamic properties, suggest the possibility of protein native state destabilization due to protein-protein and protein-metabolite interactions, altered solvent and metabolite behavior, and non-specific interactions between functionally related enzymes as a result of crowding. Some of the work described involves very large scale computer simulations that were enabled by methodological advances that will also be briefly discussed.

TBA

02/01/17 4:15pm

MIT Building 4, Room 163

Mark Tuckerman

New York University




Mark Tuckerman

TBA

02/22/17 4:15pm

MIT Building 4, Room 163

Adam Willard

Massachusetts Institute of Technology




Adam Willard

TBA

03/01/17 4:15pm

MIT Building 4, Room 163

Martin Head-Gordon

University of California, Berkeley




Martin Head-Gordon

TBA

03/08/17 4:15pm

MIT Building 4, Room 163

Sharon Hammes-Schiffer

University of Illinois at Urbana-Champaign




Sharon Hammes-Schiffer

TBA

03/15/17 4:15pm

MIT Building 4, Room 163

Ronnie Kosloff

Hebrew University




Ronnie Kosloff

TBA

03/22/17 4:15pm

MIT Building 4, Room 163

Ken Dill

Stony Brook University




Ken Dill

TBA

04/12/17 4:15pm

MIT Building 4, Room 163

Weitao Yang

Duke University




Weitao Yang

TBA

04/19/17 4:15pm

MIT Building 4, Room 163

So Hirata

University of Illinois at Urbana-Champaign




So Hirata

TBA

04/26/17 4:15pm

MIT Building 4, Room 163

Dominika Zgid

University of Michigan




Dominika Zgid

TBA

05/03/17 4:15pm

MIT Building 4, Room 163

Katja Lindenberg

University of California, San Diego




Katja Lindenberg

TBA

05/10/17 4:15pm

MIT Building 4, Room 163

Ivet Bahar

University of Pittsburgh




Ivet Bahar

Past Schedules