TAMie Force Field\nfor Alkanethiols: Multifidelity\nGaussian Processes for Dealing with Scarce Experimental Data

This study extends the transferable anisotropic Mie potential\n(TAMie)\nto alkanethiols. The force field parameters are optimized by using\nan analytic equation of state as a surrogate model. Given the lack\nof experimental density data at elevated temperatures where Monte\nCarlo simulations have high statistical precision, the equation of\nstate is supplemented by a linear multifidelity Gaussian process approach\nto bridge the temperature gap. Force field parameters are adjusted\nby minimizing squared deviations of calculated vapor pressures and\nliquid densities from experimental data of 1-propanethiol, 1-butanethiol\nand 1-pentanethiol leading to small mean absolute relative deviations\nin liquid densities and vapor pressures. The force field is transferable\nto higher 1-thiols, as shown for 1-hexanethiol and 1-octanethiol.\nIndividual parameter sets are provided for methanethiol and ethanethiol.\nThe shear viscosity of pure substances is predicted in fair agreement\nwith experimental data, considering that it is not included in the\nparametrization. Further, the phase behavior of binary mixtures of\nalkanethiols\nwith alkanes is studied, and predictions of the TAMie model are found\nin excellent agreement with experimental data.