Jason R. Green

Assistant Professor of Chemistry (September 2012-)
University of Massachusetts Boston
green.jason.r@gmail.com

Research opportunities beginning Fall Semester 2012

Our research is concerned with the manipulation and transport of matter and energy, particularly on the molecular scale. We construct theories and computational tools to characterize, understand, and control processes far from thermodynamic equilibrium. We implement theories as algorithms in massively parallel computer programs that simulate molecular dynamics. A long term goal is to use our new approaches to design atom- and energy-efficient syntheses of dynamic nanostructured materials and complex biological matter with tailored properties.

What are nonequilibrium processes?

Phenomena occurring far from thermodynamic equilibrium redistribute and manipulate energy. They are ubiquitous in our everyday experience, from the processes underlying the operation of living systems to those responsible for weather and climate. Matter driven out of equilibrium has evolving properties, structures, and patterns different from those found under equilibrium conditions. In the laboratory this fact is being exploited: for example, matter is manipulated at the molecular and supramolecular level to create structures and materials, impacting nanoscience, engineering, and technology. However, fundamental advances have been hindered by the lack of general, unifying principles and absence of a microscopic theory for processes arbitrarily far from equilibrium.

What do we do?

We are working towards these general, unifying principles and a microscopic theory for nonequilibrium processes. Our research develops theories and computer simulation methods, in part, to determine the efficiency and limitations of energy transport. We perform, develop, and apply physics-based models of molecules and numerical analysis techniques to simulate, evaluate, and solve problems. Technically, our research is in the field of theoretical and computational chemistry, but it makes use of computer science and mathematics, and draws inspiration from biology.

Why do we do it?

A primary aim of our research is to predict experimental results for a diverse range of energetically driven nanoscale systems, from photo-switchable and dynamically aggregating nanoparticles to single, vibrationally excited molecules. Another goal is a microscopic theory of nonequilibrium processes, which will determine the maximum useful work small systems can perform while out of equilibrium. With new understanding of the energy dissipated or "wasted" by nanoscale devices and molecules, these systems will be subject to more informed design and control. Harnessing dissipated energy will then lead to new synthetic routes to dynamic nanostructured materials and complex biological matter.

What do we have?

1. Cutting edge theoretical and computational methods; 2. our own massively parallel and efficient computer codes that execute on graphics processors and simulate molecular dynamics; 3. a diverse and interdisciplinary set of fascinating out-of-equilibrium problems; 4. the ability to change quickly between and solve problems at the interface of several scientific fields; 5. exciting research projects.

Example research projects

If any of these projects are of interest to you (or if you are generally interested in computational chemistry) please contact Jason.

Forced flow in confined environments (figure shown above): Transport through geometrically confined spaces is ubiquitous in biological cells, ion channels, nano-porous materials, zeolites and microﬂuidic devices. The driving forces behind transport and the geometric restrictions influence the system's dynamics and regulate the transport of particles. The study of the kinetics of the entropic transport and transport control mechanisms will be of interest as we dynamically characterize those systems with molecular dynamics simulations.

test Control of molecular motion: A fundamental goal of chemistry research is to drive chemical reactions to most efficiently give desired products. We will use and develop new theoretical and computational methods to explore how vibrational excitation of reactant molecules in different environments can influence the outcome of chemical reactions. Using simulations we will study the transfer of energy between the environment and the reactive system.

Theory of nonequilibrium statistical mechanics: The theory of statistical mechanics bridges the hidden inner motion of microscopically invisible components of matter and a diverse range of macroscopically observable phenomena. There is (at present) no truly unified, coherent theory of nonequilibrium phenomena; there are no basic, unifying principles (analogous to those of the laws of thermodynamics) capable of organization and prediction. We are searching for a unified theory of statistical mechanics based upon our fundamental limits to predict molecular motion.