The deuterium quadrupole interaction in ND 3

The hyperfine structure of the J = K = 1 and J = K = 4 inversion transitions of ND ₃ has been observed by molecular beam electric resonance with a resolution of approximately 300 Hz. The 4-4 spectrum confirms the hypothesis given by Garvey et al. [ Mol. Phys., 31, 205 (1976)] of an error by a factor of 1.38 in the frequency calibration of the data by Basov and Bashkin [ JETP Lett., 8, 188], bringing their results into agreement with observations on other states. The 1-1 spectrum gives a value of 159.0 kHz for the interaction 2∆=(eQ/2)[{∂2V}/{∂x}-{∂2V}/{∂y}] .