Spin Interactions of Accelerated Nuclei in Molecules

The contributions to the spin-rotational magnetic interaction of a nucleus in a molecule of terms dependent on the acceleration of the nucleus are calculated. One of these arises from the fact that the acceleration in molecules is electrical and the moving nuclear magnetic moment interacts with the electric field. The other is the Thomas precession similar to that which occurs for electrons in atoms. The effects of both centripetal acceleration and zero-point vibration acceleration are considered; the latter produces the largest effect. A general expression for the combined effect of these terms is given. When it is averaged over the zero point vibration of the ${\mathrm{H}}_2$ and ${\mathrm{D}}_2$ molecules, the contribution to the spin-rotational interaction constant $c$ is 1059 cps for ${\mathrm{H}}_2$ and 30.6 cps for ${\mathrm{D}}_2$.