Ab Initio Atom-Atom Potentials Using CAMCASP: Theory and Application to Many-Body Models for the Pyridine Dimer
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Publication Date
2016-07-28Journal Title
Journal of Chemical Theory and Computation
ISSN
1549-9618
Volume
12
Issue
9
Pages
4184-4208
Type
Article
Metadata
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Misquitta, A., & Stone, A. (2016). Ab Initio Atom-Atom Potentials Using CAMCASP: Theory and Application to Many-Body Models for the Pyridine Dimer. Journal of Chemical Theory and Computation, 12 (9), 4184-4208. https://doi.org/10.1021/acs.jctc.5b01241
Abstract
Creating accurate, analytic atom−atom potentials for small organic molecules from first principles can be a
time-consuming and computationally intensive task, particularly if we also require them to include explicit polarization
terms, which are essential in many systems. We describe how
the CamCASP suite of programs can be used to generate such
potentials using some of the most accurate electronic structure
methods currently applicable. We derive the long-range terms
from monomer properties and determine the short-range
anisotropy parameters by a novel and robust method based on
the iterated stockholder atom approach. Using these
techniques, we develop distributed multipole models for the
electrostatic, polarization, and dispersion interactions in the
pyridine dimer and develop a series of many-body potentials for the pyridine system. Even the simplest of these potentials
exhibits root mean square errors of only about 0.6 kJ mol −1 for the low-energy pyridine dimers, significantly surpassing the best
empirical potentials. Our best model is shown to support eight stable minima, four of which have not been reported before in the
literature. Further, the functional form can be made systematically more elaborate so as to improve the accuracy without a
significant increase in the human-time spent in their generation. We investigate the effects of anisotropy, rank of multipoles, and
choice of polarizability and dispersion models.
Identifiers
External DOI: https://doi.org/10.1021/acs.jctc.5b01241
This record's URL: https://www.repository.cam.ac.uk/handle/1810/261101
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