Development and Application of Multicentered Integrated Methods for Weakly-Bound Non-Covalent Clusters

University Of Mississippi, University MS

Investigators

Abstract

Gregory Tschumper of the University of Mississippi has received an award from the Theory, Models and Computational Methods. The project focuses on high accuracy electronic structure characterization of molecular clusters held together by weak non-covalent interactions such as hydrogen bonding and dispersion interactions. Non-covalent clusters have significance in almost every area of the physical and biological sciences, playing key roles in everything from solvation to the physical, chemical, and electronic properties of materials in the solid phase. The project has two goals: (1) Development and implementation of multi-centered (MC) integrated electronic structure methods (e.g., MO:MO, QM:QM, QM:MM and ONIOM) for the evaluation of molecular properties such as dipole moments, harmonic vibrational frequencies, NMR shielding constants among others; and (2) Application of the methodology for studying chemical physics of water clusters and micro-solvation phenomena. Of particular interest are the electronic and vibrational structure of water clusters at the crossover from 2D to 3D hydrogen bonding networks, the blue-shifted vibrational frequencies of azabenzenes in the condensed phase, and the relationship between the energy of complexation and solvent polarity for aromatic ¼-type interactions between "electron rich" 1,5-dialkoxynaphthalenes and "electron deficient" 1,4,5,8-naphthalenetetracarboxylicdiimides.Broader impact activities include a continued effort to mentor female and underrepresented students at the undergraduate and graduate level. Software developed during the project is made freely available. In addition, the large body of benchmark data generated as a by-product during the calibration of the MC integrated technique is collected, organized and distributed in a public and accessible database.