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Ab initio derived force-field parameters for molecular dynamics simulations of deprotonated amorphous-SiO 2/water interfaces

: Butenuth, A.; Moras, G.; Schneider, J.; Koleini, M.; Köppen, S.; Meißner, R.; Wright, L.B.; Walsh, T.R.; Ciacchi, L.C.

Fulltext urn:nbn:de:0011-n-2069354 (2.3 MByte PDF)
MD5 Fingerprint: 4ebc4f76f3e7d79d7e5b0b10622a7773
Created on: 3.5.2016

Physica status solidi. B 249 (2012), No.2, pp.292-305
ISSN: 0031-8957
ISSN: 0370-1972
European Commission EC
FP7-NMP; 229205; ADGLASS
Deutsche Forschungsgemeinschaft DFG
Journal Article, Electronic Publication
Fraunhofer IWM ()
Fraunhofer IFAM ()

We present a set of Coulomb point charges and van der Waals parameters for molecular dynamics simulations of interfaces between natively deprotonated amorphous SiO 2 surfaces and liquid water, to be used in combination with standard biomolecular force fields. We pay particular attention to the extent of negative charge delocalisation in the solid that follows the deprotonation of terminal silanol groups, as revealed by extensive Bader analysis of electronic densities computed by density functional theory (DFT). The absolute charge values in our force field are determined from best-fitting to the electrostatic potential computed ab initio (ESP charges). Our proposed parameter set is found to reproduce the energy landscape of single water molecules over neutral and deprotonated amorphous SiO 2 surfaces and, after a minor adjustment, over thin oxide films on Si. Our analysis reveals a certain degree of arbitrariness in the choice of the DFT scheme used as the reference for the force-field optimisation procedure, highlighting its intrinsic limits.