Beyond Geometry Description for Materials Characterization: Use Total Bond Order Density

 

Wai-Yim Ching

University of Missouri-Kansas City, Missouri, 64110 USA

​

ABSTRACT:

 

For over a century, materials research and their characterization are mostly based on geometrical description of the constituent atoms such as atomic radii, coordination number, bond length and bond angle distributions. Such approach has been extremely successful in advancing materials research and in simulation. The potential functions used in most classical molecular dynamics simulations are usually based on the parameters derived from these geometric descriptions. However, there has been a growing awareness that purely geometric description is far from adequate for complex materials such as multicomponent glasses or alloys, interphases with complex structures, systems dopants and defects, and especially in biomolecular systems where the effect of solvation and hydrogen bonding play a key role. In this talk, I advocate the use of total bond order density (TBOD) as a single quantum mechanics matric to replace geometric descriptions. TBOD is the sum of bond order values between all pairs of atoms normalized by its volume. The effeteness of this approach is demonstrated in its application to many materials systems such as cements, alkali-doped silicate glasses, multicomponent metallic glasses, organic glasses and solvated biomolecular systems.

​

BIOGRAPHIE:

​

Dr. Wai-Yim Ching is a Distinguished Curators’ Professor of Physics at the University Missouri-Kansas City, USA. He leads the Electronic Structure Group (ESG) in the Department of Physics and Astronomy. His research focuses on condensed matter theory and computational materials science using first-principles methods. With more than 40 years of experience, he is an author or co-author of over 410 journal articles in diverse areas related to materials and with a Google Scholar Citation H-index 64.  He is an Academician of World Ceramic Academy, a Fellow of the American Ceramic Society and the American Physical Society. He is an Associate Editor of the Journal of the American Ceramic Society and is on the Editorial Board of Nature Scientific Reports. (119 words)