Chemical reaction dynamics within anisotropic solvents in time-dependent fields

Quantum Chemical Reaction Dynamics

This section describes the research efforts and progress made for the implementation and performance of the quantum mechanical reactive scattering application (3D-REACT) across CASA heterogeneous computer environments with nodes that can reside at geographically different locations. This is a scientifically and technically important application. The formalism uses a symmetrized hyperspherical c...

Chemical reaction dynamics.

Understanding the motions of the constituent atoms in reacting molecules lies at the heart of chemistry and is the central focus of chemical reaction dynamics. The most detailed questions one can ask are about the evolution of molecules prepared in a single quantum state to products in individual states, and both calculations and experiments are providing such detailed understanding of increasi...

Large scale reaction front dynamics in anisotropic reaction-diffusion systems

Dynamics of Berry-phase polarization in time-dependent electric fields

We consider the flow of polarization current J5dP/dt produced by a homogeneous electric field E(t) or by rapidly varying some other parameter in the Hamiltonian of a solid. For an initially insulating system and a collisionless time evolution, the dynamic polarization P(t) is given by a nonadiabatic version of the KingSmith–Vanderbilt geometric-phase formula. This leads to a computationally con...

Exact quantum dissipative dynamics under external time–dependent fields driving

Exact and nonperturbative quantum master equation can be constructed via the calculus on path integral. It results in hierarchical equations of motion for the reduced density operator. Involved are also a set of well– defined auxiliary density operators that resolve not just system–bath coupling strength but also memory. In this work, we scale these auxiliary operators individually to achieve a...