Long-range spherical potential energy function from the second virial coefficient using decomposition into subspaces

Abstract

The long-range dispersion part of a spherical potential energy function was recovered from simulated second virial data for the Ar–Ar system in the temperature range 90⩽T/K⩽120. Using the singular value decomposition method the potential was obtained for several dimensions of the four basic subspaces. In particular for the data generated and for dimension of the nullspace equal to two the potential was recovered almost exactly. For a larger basis set, n = 128, where the simulated data would be in error by 3.5% when compared with the experimental data, the potential could be recovered, using the stationary points, within an error of 0.3–2.0%. The present procedure also indicates a general strategy, when handling second virial experimental data in the low temperature region, to obtain the long-range part of the spherical potential function.