DEVELOPMENT AND PARAMETERIZATION OF A MULTI-PURPOSE ATOMIC AND MOLECULAR POTENTIAL ENERGY FUNCTION

Abstract

Simulations of solid, liquid and gaseous state systems require the use of molecular force fields to extract physical and chemical properties at bulk level. Molecular force fields normally include covalent bond stretching energy and van der Waals interaction energy, among others. Most conventional computational chemistry applications adopt the harmonic potential for bond stretching while the Morse function is employed for the greater accuracy.

To a lesser extent, the Linnett potential has been proposed for describing bond-stretching energy. Neutral non-bonded interaction energy is often modeled by the Lennard-Jones potential, and the Expoential-6 function (the latter falls under the category of the Buckingham potential). So far, covalent bonds stretching energy and van der Waals interaction energy have been described by different groups of potential functions due to their comparative suitability.

The use of a single potential function across various types of bonding and molecular sizes will help the development of multi-scale analysis die to the smooth transition of energy quantification from one scale to another. Therefore, in this project, a blended potential energy function is to be conceptualized for describing both covalent bond and van der Waals energy. The obtained parameters for Si-Si and other Si-related interactions will be of use in modeling the characteristics of nano-electronic materials and devices.