Accurate non-bonded potentials based on periodic quantum mechanics calculations for use in molecular simulations of materials and systems
Abstract
Molecular dynamics simulations require accurate force fields (FFs) to describe the physical and chemical properties of complex materials and systems. FF parameters for valence interactions can be determined from high-quality Quantum Mechanical (QM) calculations. However, it has been challenging to extract long-range nonbonded interaction potentials from QM calculations since there is no unambiguous method to separate the total QM energy into electrostatics (polarization), van der Waals (vdW), and other components. Here, we propose to use density functional theory with dispersion corrections to obtain the equation of state for single element solid systems (of H, C, N, O, F, Cl, Br, I, P, He, Ne, Ar, Kr, Xe, and Rn) from which we obtain the pure 2-body vdW nonbonded potentials. Recently, we developed the polarizable charge equilibration (PQEq) model based on QM polarization energy of electric probe dipoles with no contributions from vdW. Together, the vdW and PQEq interactions form the nonbonded potential of our new transferrable reactive FF (RexPoN). They may also be useful to replace the nonbonded parts of standard FFs, such as OPLS, Amber, UFF, and CHARMM. We find that the individual 2-body vdW potential curves can be scaled to a universal vdW potential using just three specific atomic parameters. This simplifies extension to the rest of the periodic table for atoms that do not exhibit molecular packing. We validate the accuracy of these nonbonded interactions for liquid water, energetic, and biological systems. In all cases, we find that our new nonbonded potentials provide good agreement with QM and experimental data.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 18, 2019
- Source ID
- 10.1063/1.5113811
Entities
People
- Hao Yang
- Julius J Oppenheim
- Mohamed Rizk
- Saber Naserifar
- Sergey Zybin
- Tingting Zhou
- William Andrew Goddard III
Organizations
- California Institute of Technology
- Institute of Applied Physics and Computational Mathematics
- National Science Foundation
- Office of Basic Energy Sciences
- Office of Naval Research
- United States Department of Energy