Since the NO molecule has a finite electronic angular momentum $\frac{\hslash }{2}$ along the molecular axis in its ground state, the Stark effect of this molecule is very large, the molecule being effectively a symmetric top molecule rather than a diatomic molecule. The calculation is made both for weak-field and strong-field cases. An experiment by Burrus and Graybeal has been done for weak fields and gives $\mu =0.158\mathrm{}$ Debye unit. The dielectric constant of this molecule is also discussed and it is shown that the ordinary Langevin-Debye formula can be used with the effective dipole moment ${\mu }_{\mathrm{eff}}=0.971\mathrm{}$ μ.

• Received 21 October 1957

DOI:https://doi.org/10.1103/PhysRev.109.1557