library(chapensk)

CH4 <- Gas("methane")
Ar <- Gas("argon")
# virial coefficient
stopifnot(round(1E6 * CH4$B(T = 300), 0) == -41)
# viscosity
stopifnot(round(1E6 * CH4$viscosity(T = 300), 1) == 11.2)
# density
stopifnot(round(CH4$density(T = 300), 3) == 0.652)
# diffusion coefficient
stopifnot(round(1E4 * CH4$diffusion(T = 300), 3) == 0.199)
# thermal conductivity
stopifnot(round(Ar$thermal_conductivity(T = 300), 3) == 0.018)
# polar molecule
HCl <- Gas("hydrogen chloride")
HCl$viscosity(T = 300)