Volume-Dependent Atomic Polarizabilities for Vibrational Spectroscopy
Abstract
Vibrational spectroscopy methods, such as Raman and SFG, are valuable tools for characterizing the structure and dynamics of a wide range of systems. Computing spectra from MD simulations remains a signficant challenge, as accurate polarizabilities (α) are required for a large range of molecular configurations, and ab-initio α can be prohibitively expensive to compute for even small molecules. We extend the Thole model by making the initial atomic α functions of the interatomic distances, scaling them by the radius of the atom as defined by the volume the atom occupies in the molecule. This allows us to compute accurate α for molecules far from their equilibrium configuration. We then compute accurate Raman spectra of water and urea, and SFG spectra at the alumina-water interface.
This work was supported by the Center for Complex Materials, an Energy Frontier Research Center funded by the U.S. Dept. of Energy, Office of Science, Basic Energy Sciences, (Grant DE-SC0012575). and includes calculations carried out on Temple University's HPC resources and thus was supported in part by the National Science Foundation through major research instrumentation Grant Number 1625061 and by the US Army Research Lab. under contract W911NF-16-2-0189.- Publication:
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APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARP16006D