Knowledge Bank

Hundreds of very sharp spectral lines with typical linewidth of $\sim 20$ MHZ have been observed around the $Q1\leftarrow 0(1)$ transition (at $4146.5673cm-1$) of $O-H2$ impurity in a sample of solid $p-H2(\sim 99.8\%)$ at 4.2 K. The spectrum from 4137 to $4154cm-1$ was recorded using a 115 mm long cell and a difference frequency laser spectroseter with tone-burst modulation. Transition frequencies are reproducible but the intensity changes as O-H2 concentration varies. The complexity of the spectrum may be ascribed to orientational splittings of pairs of $O.H2$ molecules by EQQ interactions. The preliminary analysis will be discussed. $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$W.N. Hardy and A.J. Berlinsky, Phys. Rev. Lett. 34. 1520 (1975). MITCHIO OKUMURA, Division of Chemistry, California Institute of Technology, Pasadena, California 91125