Thermal accommodation coefficients (TAC) between aluminum and noble gases were studied with molecular dynamics (MD) simulations. Gases interacting with aluminum substrates were modeled by MD with gas velocities sampled from the Maxwell-Boltzmann distribution to give accumulated TAC results. Different implementations of the equation to calculate the TAC, which differ in the amount of information gleaned from MD and the corresponding simulation results, were carefully discussed. The best formula for MD modeling in finite simulation time was determined. Additionally, the influence of the combining rules applied on aluminum-noble gas interatomic potential was characterized with the well-known Lennard-Jones 12-6 potential combined with Lorentz-Berthelot and Fender-Halsey mixing rules. The results were compared with experimental values and previous analytical model. TACs simulated with Fender-Halsey rules present excellent agreement with the experimental values. Detailed TAC distributions and accumulated TAC convergence are also included. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 338-345, 2018