title: A generalized force-modified potential energy surface for mechanochemical simulations.
abstract: We describe the modifications that a spatially varying external load produces on a Born-Oppenheimer potential energy surface (PES) by calculating static quantities of interest. The effects of the external loads are exemplified using electronic structure calculations (at the HF/6-31G(∗∗) level) of two different molecules: ethane and hexahydro-1,3,5-trinitro-s-triazine (RDX). The calculated transition states and Hessian matrices of stationary points show that spatially varying external loads shift the stationary points and modify the curvature of the PES, thereby affecting the harmonic transition rates by altering both the energy barrier as well as the prefactor. The harmonic spectra of both molecules are blueshifted with increasing compressive "pressure." Some stationary points on the RDX-PES disappear under application of the external load, indicating the merging of an energy minimum with a saddle point.
authors.affiliation: School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, Mississippi 39402, USA.
authors.forename: Gopinath
authors.initials: G
authors.lastname: Subramanian
authors.affiliation: Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
authors.forename: Nithin
authors.initials: N
authors.lastname: Mathew
authors.affiliation: Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: Leiding