This title appears in the Scientific Report : 2013 

Modelling the Dielectric Response of Atomistic and Continuous Media with the Split-Charge Method
Müser, Martin (Corresponding author)
Jülich Supercomputing Center; JSC
Hybrid Particle-Continuum Methods in Computational Materials Physics
Jülich John von Neumann Institute for Computing (NIC) 2013
Hybrid Particle-Continuum Methods in Computational Materials Physics, Jülich (Germany), 2013-03-04 - 2013-03-07
Contribution to a book
Contribution to a conference proceedings
Computational Science and Mathematical Methods
NIC Series 46
Many processes involving ions, polar molecules, or polar moieties take place in an external medium with heterogeneous dielectric properties. Examples range from protein folding in a polarizable solvent to contact electrification induced by the rubbing of two dislike solids. When simulating such processes, it is not appropriate to decompose the electrostatic forces between the central atomistic degrees of freedom into (effective) two-body contributions. Instead, one needs to consider the dielectric response of the external medium, which one may want to represent as a continuum. In this contribution, we show that the split-charge equilibration (SQE) method can be used to describe continua with well-defined dielectric properties, although it was originally designed to assign atomic charges on the fly. As such, SQE bears much potential for hybrid particle-continuum simulations. The comparison of dielectric response functions as obtained by SQE and point-dipole methods reveals many advantages for SQE. The main points are: SQE requires fewer floating-point operations, non-local dielectric properties are more easily embedded, and the leading-order corrections to the continuum limit are isotropic on the simple cubic lattice in contrast to point dipole models.