6533b7d2fe1ef96bd125ebf9
RESEARCH PRODUCT
Amorphous silica modeled with truncated and screened Coulomb interactions: A molecular dynamics simulation study
Walter KobJürgen HorbachSimona IspasLudovic BerthierAntoine Carresubject
PhysicsStatistical Mechanics (cond-mat.stat-mech)010304 chemical physicsCoulomb interactionsStructure (category theory)FOS: Physical sciencesGeneral Physics and Astronomymolecular dynamics computer simulationYukawa interactionEwald sums01 natural sciencesMolecular physicsEwald summationAccelerationMolecular dynamicssilica0103 physical sciencesCoulombCutoffPhysical and Theoretical Chemistry[PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech]010306 general physicsPair potentialCondensed Matter - Statistical Mechanicsdescription
We show that finite-range alternatives to the standard long-range BKS pair potential for silica might be used in molecular dynamics simulations. We study two such models that can be efficiently simulated since no Ewald summation is required. We first consider the Wolf method, where the Coulomb interactions are truncated at a cutoff distance r_c such that the requirement of charge neutrality holds. Various static and dynamic quantities are computed and compared to results from simulations using Ewald summations. We find very good agreement for r_c ~ 10 Angstroms. For lower values of r_c, the long--range structure is affected which is accompanied by a slight acceleration of dynamic properties. In a second approach, the Coulomb interaction is replaced by an effective Yukawa interaction with two new parameters determined by a force fitting procedure. The same trend as for the Wolf method is seen. However, slightly larger cutoffs have to be used in order to obtain the same accuracy with respect to static and dynamic quantities as for the Wolf method.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2007-09-21 |