The effectiveness of various temperature control algorithms (Gaussian, generalized Gaussian moment thermostat, velocity scaling, Nosé-Hoover, Nosé-Hoover chain) for dual control volume grand canonical molecular dynamics was investigated for the study of H atom diffusion in bulk Pd. The 5 algorithms were examined in both equilibrium and non-equilibrium simulation studies. The numerical results showed that the Gaussian algorithm yielded the most inaccurate solutions for the H-Pd system, due to the high friction coefficient which was generated by the large velocity fluctuation of H. The Nosé-Hoover chain, Nosé-Hoover and generalized Gaussian moment thermostat algorithms produced the most accurate temperature and density profiles in both equilibrium and non-equilibrium cases with their feedback control mechanisms. However, this feedback control also over-estimated the self-diffusion coefficients in equilibrium systems and the diffusion coefficient in non-equilibrium systems. The velocity scaling thermostat produced slight inhomogeneities in the temperature and density profiles but, due to the dissipated heat accumulated in the control volumes, it still yielded accurate self-diffusion coefficients that were in good agreement with experimental data over a wide range of temperatures, while others tended to deviate.

Temperature Control Algorithms in Dual Control Volume Grand Canonical Molecular Dynamics Simulations of Hydrogen Diffusion in Palladium. J.Sun, L.T.Zhang: Journal of Chemical Physics, 2007, 127[16], 164721