Assessment of the “methodological” uncertainty of molecular dynamics simulations based on an ultra-accurate potential of helium-4 dimers

Abstract

The internal energy and pressure of helium fluids were calculated by molecular dynamics simulations using the best abinitio potential. The considered temperature range is from 300 K to 2000 K and the maximum density is 17 mol/ L. Because of the ultra-low uncertainty of the potential model, the computed values of helium are considered to be a standard and were used to define the uncertainty of simulation methods by comparing with the reference data. Our results of internal energy, pressure, and method uncertainty and these values in reduced forms were reported in the Supplement materials. The behaviors of method uncertainty as a function of reduced temperature and reduced density for different properties at different phases were discussed. The recommendation was given on the applications of our uncertainty results in future thermophysical property simulations of other monatomic fluids.