The Rotational Stark Spectrum of Linear Molecules

In the electric resonance method of radiofrequency spectroscopy various molecular and nuclear parameters of linear polar molecules may be determined from observations of the 1, 0→1, ±1 transition. An equation is given for the energy difference of these two states which is good to terms in ${\lambda }^6$ up to values of $\lambda =1.0\mathrm{}$, where $\lambda$ is a quantity which is proportional to the electric field strength. From this equation, expressions are derived for the permanent electric dipole moment and the moment of inertia in terms of experimentally determined parameters.