Development of an empirical force field for silica. Application to the quartz-water interface.

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TitleDevelopment of an empirical force field for silica. Application to the quartz-water interface.
Publication TypeJournal Article
Year of Publication2006
AuthorsLopes, PEM, Murashov, V, Tazi, M, Demchuk, E, Mackerell, AD
JournalJ Phys Chem B
Date Published2006 Feb 16
KeywordsAdsorption, Hydrogen Bonding, Models, Chemical, Molecular Conformation, Quantum Theory, Silicon Dioxide, Surface Properties, Vibration, Water

Interactions of pulverized crystalline silica with biological systems, including the lungs, cause cell damage, inflammation, and apoptosis. To allow computational atomistic modeling of these pathogenic processes, including interactions between silica surfaces and biological molecules, new parameters for quartz, compatible with the CHARMM empirical force field were developed. Parameters were optimized to reproduce the experimental geometry of alpha-quartz, ab initio vibrational spectra, and interactions between model compounds and water. The newly developed force field was used to study interactions of water with two singular surfaces of alpha-quartz, (011) and (100). Properties monitored and analyzed include the variation of the density of water molecules in the plane perpendicular to the surface, disruption of the water H-bond network upon adsorption, and space-time correlations of water oxygen atoms in terms of Van Hove self-correlation functions. The vibrational density of states spectra of water in confined compartments were also computed and compared with experimental neutron-scattering results. Both the attenuation and shifting to higher frequencies of the hindered translational peaks upon confinement are clearly reproduced by the model. However, an upshift of librational peaks under the conditions of model confinement still remains underrepresented at the current empirical level.

Alternate JournalJ Phys Chem B
PubMed ID16471886
PubMed Central IDPMC2531191
Grant List200-2000-08026 / / PHS HHS / United States
GM51501 / GM / NIGMS NIH HHS / United States
R01 GM051501-11 / GM / NIGMS NIH HHS / United States
R01 GM051501 / GM / NIGMS NIH HHS / United States
R29 GM051501 / GM / NIGMS NIH HHS / United States