Texas Tech University
TTU HomeDepartment of Chemistry and Biochemistry Faculty Dr. William L. Hase

Dr. William L. Hase


Paul Whitfield Horn Professor, Robert A. Welch Chair


Ph.D., New Mexico State University, 1970; Postdoctoral Study, New Mexico State University, 1970-71; Postdoctoral Study, University of California-Irvine, 1971-73

Research Area:

Computational, Theoretical, and Physical Chemistry





Chemistry 336





Research Group

Research Web Site

Principal Research Interests

Dr. Hase’s research group simulates the dynamics of molecular motion and chemical reaction at an atomistic, microscopic level.  Classical, semi-classical, and quantum mechanical methods are used for the simulations, which are used to compare with experiments and to test and develop theoretical models of molecular motion and chemical reactivity.  Computer graphics are used to animate and visualize the simulations.  For many chemical problems classical mechanics provides an accurate description of atomic motion and the Hase research group has developed the VENUS computer program for performing classical trajectory simulations.  Calculating a classical trajectory or the motion of a semi-classical/quantum wave packet requires the derivatives of the potential energy with respect to the coordinates of each of the atoms.  In a direct dynamics simulation these derivatives are obtained directly from a quantum chemistry (QM) electronic structure theory.  To perform this type of simulation VENUS is interfaced with quantum chemistry computer programs.  For large-scale simulations, a QM/MM calculation may be performed in which part of the potential is represented by both a quantum mechanical theory and the remainder by molecular mechanical (MM) analytic potential energy functions.  Dr. Hase also advises computer science graduate students whose research is in the area of scientific computing; i.e. they develop computer programs for the simulations and structure the programs so that they run efficiently in a high-performance computing environment.  Dr. Hase is co-author of the books Chemical Kinetics and Dynamics and Unimolecular Reaction Dynamics. Theory and Experiments.

The current simulations of Dr. Hase’s research group include collision- and surface-induced dissociation (CID and SID) of ions (including peptides), the dynamics of gas phase SN2 nucleophilic substitution reactions, intramolecular and unimolecular dynamics of reactive intermediates, energy transfer and chemical reaction in collisions of ions and radicals with surfaces, structures of liquid surface interfaces, and adhesion, friction, lubrication, and wear of sliding surfaces.  The figure shown below is a chemical dynamics simulation of the SID of protonated diglycine.  The peptide shatters as it collides with the diamond {111} surface, forming H2 + NHCH2 + CONHCH2COOH+.


Representative Publications