Validation of intermolecular pair potential model of SiH4: Molecular-dynamics simulation for saturated liquid density and thermal transport properties

Abstract

We demonstrate a validation of the intermolecular pair potential model of SiH(4), which is constructed from ab initio molecular-orbital calculations and expressed as the sum of the exponential and the London dispersion terms. The saturated liquid densities of SiH(4) are calculated for temperatures from 100 to 225 K by molecular-dynamics (MD) simulation. The average deviation between the experiment and the MD simulation using the present potential model is 3.9%, while the deviations exceed 10% for other well-known potential models such as the five-center Lennard-Jones (LJ) model. Subsequently, the shear viscosity, the thermal conductivity, and the self-diffusion coefficient of liquid SiH(4) are calculated by an equilibrium MD simulation with the Green-Kubo formula from 100 to 225 K. The average deviations from experiment are 11.8% and 13.7% for the shear viscosity and the thermal conductivity, respectively. Comparing the present model with an empirical one-center LJ model, it turns out that the rotational energy transfer through the intermolecular potential energy, which comes from the anisotropic potential energy, plays an important role in the thermal conductivity of liquid SiH(4). These results indicate that the present intermolecular potential model has an ability to give realistic pictures for liquid SiH(4) through molecular simulations.

Molecular Dynamics Simulation of Poly(ethylene terephthalate) Oligomers

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Potential energy surfaces for small alcohol dimers I: Methanol and ethanol

“…Often ab initio potentials are validated by comparing thermodynamic and structural properties obtained from molecular simulations using models regressed from the ab initio potential surface. 52,55,57,58 Generally simulated properties obtained using these ab initio-derived pair potential models compare favorably with results obtained using empirically parametrized potentials such as the optimized potentials for liquid simulation ͑OPLS͒ model. 38,59 Even more rigorous tests generally exhibit good agreement between experiment and simulation results obtained using models derived from quality ab initio potential surfaces.…”

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“…DFT calculations yielded various interaction models, both underestimating and overestimating the binding energy results. Sakiyama and co-workers [16][17][18] earlier studied the intermolecular interactions of SiH 4 -SiH 4 and SiH 4 -H 2 dimers using MP2/aug-cc-pVTz and constructed an analytical pair potential model, which they subsequently applied to calculate the thermal properties of liquid SiH 4 by MD simulation and the adsorption of SiH 4 on the Si(100) surface. Also the growth of silicon film by CVD has been the target of many studies [19][20][21].…”