  Resistive switching devices emerged a huge amount of interest as promising
candidates for non-volatile memories as well as artificial synapses due to
their memristive behavior. The main physical and chemical phenomena which
define their functionality are driven by externally applied voltages, and the
resulting electric fields. Although molecular dynamics simulations are widely
used in order to describe the dynamics on the corresponding atomic length and
time scales, there is a lack of models which allow for the actual driving force
of the dynamics, i.e. externally applied electric fields. This is due to the
restriction of currently applied models to either solely conductive,
non-reactive or insulating materials, with thicknesses in the order of the
potential cutoff radius, i.e., 10 \r{A}. In this work, we propose a generic
model, which can be applied in particular to describe the resistive switching
phenomena of metal-insulator-metal systems. It has been shown that the
calculated electric field and force distribution in case of the chosen example
system Cu/a-SiO$_2$/Cu are in agreement with fundamental field theoretical
expectations.
