where formula_84 is a numerical factor which in general depends on the molecular model. For smooth spherically symmetric molecules, however, formula_84 is very close to formula_86, not deviating by more than formula_87 for a variety of interparticle force laws. Since formula_1, formula_82, and formula_62 are each well-defined physical quantities which can be measured independent of each other, this expression provides a convenient test of the theory. For monatomic gases, such as the noble gases, the agreement with experiment is fairly good.