Knowledge Bank

Hyperfine structure in the $313\to 302$ rotation-inversion transition of deuterated ammonia $NH2D$ at 18,807.7 Mc/sec has been studied with a beam maser microwave spectrometer giving a linewidth of 6 kc/sec. All details of the observed hfs have been accounted for in terms of the various quadrupole, spin-rotation, and spin-spin interactions of the four nuclei. For the quadrupole coupling constant of the deuteron along the N-D bond direction $\xi$ we find that $(eV\xi \xi Q)D=256\pm 12kc/sec$, and hence for the second derivative of the potential $V\xi \xi =1.25\pm 0.06\times 1015statvolt/cm2$. This is slightly higher than the value for the coupling constant of $200\pm 20$ kc/sec found by Herrman$\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$ from the inversion spectrum of $ND3$. For the spin-rotation constants of the protons we find that $CH(313)=-13.6\pm 0.5kc/sec$, and $CH(303)=-12.4\pm 0.5kc/sec$.