Low Temperature Second Virial Coefficients for a 6–9 Potential

Alternate expressions for the second virial coefficient of a gas having a Lennard-Jones 6–9 potential are derived to cover the temperature range where the known power series expansion in θ=ε/kT is inconvenient for numerical computations. For θ≥2 the second virial coefficient can be expressed as a combination of Bessel functions of imaginary argument plus a small correction term. This formulation and an asymptotic expression derived from it are used to tabulate numerical values of the second virial coefficient in the range 2≤θ≤100.