Modified Nose-Hoover thermostat for solid state for constant temperature molecular dynamics simulation

Journal Article · Sun Jul 10 04:00:00 EDT 2011 · Journal of Computational Physics

DOI:https://doi.org/10.1016/j.jcp.2011.04.030· OSTI ID:21592599

Chen, Wen-Hwa ^[1]; Wu, Chun-Hung ^[1]; Cheng, Hsien-Chie ^[2]

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1. Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
2. Department of Aerospace and Systems Engineering, Feng Chia University, Taichung 40724, Taiwan (China)

Nose-Hoover (NH) thermostat methods incorporated with molecular dynamics (MD) simulation have been widely used to simulate the instantaneous system temperature and feedback energy in a canonical ensemble. The method simply relates the kinetic energy to the system temperature via the particles' momenta based on the ideal gas law. However, when used in a tightly bound system such as solids, the method may suffer from deriving a lower system temperature and potentially inducing early breaking of atomic bonds at relatively high temperature due to the neglect of the effect of the potential energy of atoms based on solid state physics. In this paper, a modified NH thermostat method is proposed for solid system. The method takes into account the contribution of phonons by virtue of the vibrational energy of lattice and the zero-point energy, derived based on the Debye theory. Proof of the equivalence of the method and the canonical ensemble is first made. The modified NH thermostat is tested on different gold nanocrystals to characterize their melting point and constant volume specific heat, and also their size and temperature dependence. Results show that the modified NH method can give much more comparable results to both the literature experimental and theoretical data than the standard NH. Most importantly, the present model is the only one, among the six thermostat algorithms under comparison, that can accurately reproduce the experimental data and also the T{sup 3}-law at temperature below the Debye temperature, where the specific heat of a solid at constant volume is proportional to the cube of temperature.

• OSTI ID: 21592599
• Journal Information: Journal of Computational Physics, Journal Name: Journal of Computational Physics Journal Issue: 16 Vol. 230; ISSN JCTPAH; ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
ALGORITHMS
ATOMS
CALCULATION METHODS
COMPUTERIZED SIMULATION
CONTROL EQUIPMENT
CRYSTALS
DATA
DEBYE TEMPERATURE
ELEMENTS
ENERGY
EQUIPMENT
EXPERIMENTAL DATA
GOLD
INFORMATION
KINETIC ENERGY
MATHEMATICAL LOGIC
MELTING POINTS
METALS
MOLECULAR DYNAMICS METHOD
NANOSTRUCTURES
NUMERICAL DATA
PHONONS
PHYSICAL PROPERTIES
PHYSICS
POTENTIAL ENERGY
QUASI PARTICLES
SIMULATION
SOLID STATE PHYSICS
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
THEORETICAL DATA
THERMODYNAMIC PROPERTIES
THERMOSTATS
TRANSITION ELEMENTS
TRANSITION TEMPERATURE