Inversion of diffraction data for amorphous materials

TL;DR

This paper presents a robust method combining ab initio simulations with diffraction data to accurately model amorphous materials, improving over traditional methods and applicable to diverse disordered systems.

Contribution

A new technique integrating first-principles simulations with diffraction data for better modeling of amorphous materials, demonstrated on silicon and GeSe3 systems.

Findings

Method is easy to implement and faster than conventional approaches.

Results show significant improvement in modeling accuracy.

Works for both poor and good glass-forming materials.

Abstract

The general and practical inversion of diffraction data-producing a computer model correctly representing the material explored - is an important unsolved problem for disordered materials. Such modeling should proceed by using our full knowledge base, both from experiment and theory. In this paper, we describe a robust method to jointly exploit the power of ab initio atomistic simulation along with the information carried by diffraction data. The method is applied to two very different systems: amorphous silicon and two compositions of a solid electrolyte memory material silver-doped GeSe3 . The technique is easy to implement, is faster and yields results much improved over conventional simulation methods for the materials explored. By direct calculation, we show that the method works for both poor and excellent glass forming materials. It offers a means to add a priori information in first principles modeling of materials, and represents a significant step toward the computational design of non-crystalline materials using accurate interatomic interactions and experimental information.