  In this work, we use molecular dynamics simulations to study the
thermodynamics, structure and dynamics of the Li$_2$CO$_3$-K$_2$CO$_3$ (62:38
mol%) eutectic mixture. We present a new classical non-polarizable force field
for this molten salt mixture, optimized using experimental and first principles
molecular dynamics simulations as reference data. This simple force field
allows efficient molecular simulations of phenomena at long timescales. We use
this optimized force field to describe the behavior of the eutectic mixture in
the 900-1100 K temperature range, at pressures between 0 and 5 GPa. After
studying the equation of state in these thermodynamic conditions, we present
molecular insight into the structure and dynamics of the melt. In particular,
we present an analysis of the temperature and pressure dependence of the
eutectic mixture's self diffusion coefficients, viscosity and ionic
conductivity.
