Computational Studies of the Rotational Structure of Atomic and Molecular Clusters with Weak Interactions

Utah State University, Logan UT

Investigators

Abstract

David Farrelly of Utah State University is supported by the Theoretical and Computational Chemistry Program to use diffusion Monte Carlo (DCM) methods to study the rotational structure of atomic and molecular clusters with weak interactions. The major project goal is to develop new computational approaches for examining large amplitude rotational dynamics of impurity molecules and cluster impurities in liquid helium nanodroplets, as in helium nanodroplet isolation spectroscopy. The new techniques will be generally applicable to rotational structure of assemblages of rigid top molecules in helium droplets or in the gas phase. Also, investigations will continue into ultrahigh molecular Rydberg states, with applications to zero electron-kinetic energy (ZEKE) spectroscopy. An important task in theoretical chemistry is the computation of properties of matter in unusual or extreme situations. It is often under such conditions that new and interesting properties come to light. Nanodroplets of superfluid liquid helium provide such an environment to explore molecules or small, weakly bound clusters of molecules inserted into them. Such droplets have been called the ultimate spectroscopic matrix, because of their very low temperatures and the weak influence they exert on the dopant molecules under study. These nanodroplets present significant opportunities to understand new properties of matter and fundamental solvent effects.