Failure of deterministic and stochastic thermostats to control temperature of molecular systems

Abstract: We investigate the ergodicity and "hot solvent/cold solute" problems in molecular dynamics simulations. While the kinetic moments and the stimulated Nos\'e--Hoover methods improve the ergodicity of a harmonic-oscillator system, both methods exhibit the "hot solvent/cold solute" problem in a binary liquid system. These results show that the devices to improve the ergodicity do not resolve the "hot solvent/cold solute" problem.