The effect of long-range three-body forces on the elastic constants of the inert gas solids at the absolute zero

Abstract

The elastic constants C11, C12 and C44 of neon, argon, krypton and xenon are calculated at the absolute zero. One calculation is made assuming only two-body interactions. A second calculation is then presented in which the triple-dipole interaction of Axilrod and Teller is included. It is shown that the quantity B = (C44-C12/C12, which is always positive when calculated with only two-body forces, is reduced when the triple-dipole interaction is included. In the cases of argon, krypton and xenon B in fact becomes negative. It should be possible to test this experimentally and if B were found negative this would provide strong evidence for the existence of three-body forces.