Ab Initio-Derived Force Field for Amorphous Silica Interfaces for Use in Molecular Dynamics Simulations

HS Senanayake and PN Wimalasiri and SM Godahewa and WH Thompson and JA Greathouse, JOURNAL OF PHYSICAL CHEMISTRY C (2023).

DOI: 10.1021/acs.jpcc.3c02270

We present a classical interatomic force field, silica-DDEC,todescribe the interactions of amorphous and crystalline silica surfaces,parametrized using density functional theory-based charges. Chargeschemes for silica surfaces were developed using the density- derivedelectrostatic and chemical (DDEC) method, which reproduces atomiccharges of the periodic models as well as the electrostatic potentialaway from the atom sites. Lennard-Jones parameters were determinedby requiring the correct description of (i) the amorphous silica density,coordination defects, and local coordination geometry, relative toexperimental measurements, and (ii) water-silica interatomic distancescompared with ab initio results. Deprotonated surface silanol sitesare also described within the model based on DDEC charges. The resultis a general electronic structure-derived model for describing fullyflexible amorphous and crystalline silica surfaces and interactionsof liquids with silica surfaces of varying structure and protonationstate.

Return to Publications page