抄録
The intermolecular potential of helium has been determined from an analysis of the second and the third virial coefficients above the Boyle temperature, where the virial coefficients can be expanded into power series on h2, the square of Planck’s constant. The series have been calculated up to the term proportional to the third power of h2 in case of the second virial coefficient and up to the term proportional to the first power of h2 in case of the third virial coefficient. The following conclusion has been drawn. The two-body system of He4 atoms has a discrete energy level while the two-body system of He3 atoms has no discrete level.