William Hase of Texas Tech University is supported by the Theory, Models and Computational Methods Program to enhance algorithms and software for studying chemical dynamics phenomena at short times.
Research goals comprise the development of accurate numerical implementations to compare results with experimental measurements, to determine fundamental information about intramolecular dynamics, energy transfer, and chemical dynamics. Four specific applications will be studied: i) soft-landing and reactive-landing of peptide ions on hydrocarbon surfaces for specific surface modifications; e.g. biological modifications to prepare protein microarrays, ii) surface-induced dissociation (SID) of protein multimers, iii) intrinsic non-RRKM unimolecular dynamics of low barrier isomerization reactions, and iv) post-transition state dynamics of organic reactions in condensed phases.
Chemical dynamics simulation studies will be compared with experimental results and are expected to provide new chemical knowledge. The computer programs and simulation models to be developed during the course of this project will be distributed to the scientific community, and will serve to enhance the theoretical/computational chemistry infrastructure.
This research program is in theoretical/computational chemistry and its goals are to: (1) determine more accurate theories for chemical reaction dynamics and kinetics; (2) develop algorithms and software for atomic-level simulations of chemical reactions and molecular motion; and (3) apply these simulations to a broad range of problems. The results of the simulations are compared with experiment and used to test and develop theoretical models of molecular motion and chemical reactivity. An overarching goal of our research is to develop accurate atomic-level simulation methods and software which give quite accurate results which are predictive and can give important information in the absence of experiment. A particular interest is the development of a more accurate theory for intramolecular and unimolecular dynamics. The specific research problems include: (1) SN2 nucleophilic subsitution reactions, a paradigm reaction in organic chemistry and biochemistry; (2) collisions of protonated peptide ions with surfaces; (3) reaction dynamics as a chemical system moves from a transition state to products; and (4) the calculation of accurate anharmonic vibrational frequencies for molecules. Algorithms were developed to: (1) enhance the computational speed of direct dynamics simulations using parallel, high performance computing architecture; and (2) to use semiclassical methods to calculate anharmonic vibrational frequencies for molecules, including biological molecules. These algorithms were integrated in out VENUS chemical dynamics computer program and into the VENUS/NWChem package for direct dynamics simulations. This software is distributed via our web portal cdssim.chem.ttu.edu. Animations of our simulations, which are used for both education and research, are distributed via our web portal monte.chem.ttu.edu. Post-doctoral research associates, graduate students, undergraduate students, and high school students are trained in theoretical/computational chemistry as part of this research. The research includes: (1) software development; (2) development of theoretical algorithms; (3) using high performance computing for research applications; and (4) performing chemical dynamics simulations to interpret experiments and determine new fundamental information regarding the way atoms move as chemical reactants transform to products.
