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Title: A generalized force-modified potential energy surface for mechanochemical simulations

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{sup ∗∗} 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:
 [1] ;  [2] ;  [3]
  1. School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, Mississippi 39402 (United States)
  2. Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States)
  3. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Publication Date:
OSTI Identifier:
22489670
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 13; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BORN-OPPENHEIMER APPROXIMATION; ELECTRONIC STRUCTURE; ETHANE; MOLECULES; POTENTIAL ENERGY; SIMULATION; SPECTRA; SURFACES