Simulation of electrons solvated in molten salt: A discretized path integral molecular dynamics study with quantum indistinguishability at high temperature

We present the use of discretized path integral molecular dynamics in simulating two electrons solvated in molten KCl at high temperatures. In this approach, we use an exact effective potential to simulate the singlet state (antiparallel spins), whereas we introduce an approximate effective potential for the triplet state (parallel spins). The paths for the triplet state are restricted to the region of phase space with positive density matrix. The convergence of the algorithm is presented along with the nature of the electronic states. We then discuss the validity of the introduced effective potentials by comparing our results to those obtained by another quantum molecular dynamics method which uses direct integration of the time-dependent Schrödinger equation. For this high-temperature test problem, the results come to an excellent agreement with those of previous studies.