Mixed-precision models for calculation of high-order virial coefficients on GPUs

The virial equation of state (VEOS) is a density expansion of the thermodynamic pressure with respect to an ideal-gas reference. Its coefficients can be computed from a molecular model, and become more expensive to calculate at higher order. In this paper, we use GPU to calculate the 8^th, 9^th and 10^th virial coefficients of the Lennard-Jones (LJ) potential model by the Mayer Sampling Monte Carlo (MSMC) method and Wheatley´s algorithm. Two mixed-precision models are proposed to overcome a potential precision limitation of current GPUs while maintaining the performance benefit. On the latest Kepler architecture GPU Tesla K40, an average speedup of 20 to 40 is achieved for these calculations.