A Study of the High Frequency Fundamental Bands in the Spectrum of AsH3and AsD3

An analysis has been carried out on the fundamental bands ${\nu }_1$ and ${\nu }_2$ (Dennison's notation), in the infra-red spectrum of As${\mathrm{H}}_3$. This analysis has made possible the evaluation of the reciprocals of inertia, $B$, and the Coriolis coupling coefficient, ${\zeta }_2$. These are found to be $B^{\prime \prime }=3.723\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, $B^{\prime }\left({\nu }_1\right)=3.682\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, $B^{\prime }\left({\nu }_2\right)=3.69\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ and ${\zeta }_2=-0.0602\mathrm{}$. The harmonic vibration frequencies have been computed after the method of Dennison. The values obtained are ${\omega }_1=2209.2\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\omega }_2=2225.8\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\omega }_3=973.3\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, and ${\omega }_4=1012.1\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ for the As${\mathrm{H}}_3$ molecule and ${\omega }_1=1571.2\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\omega }_2=1582.4\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\omega }_3=696\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, and ${\omega }_4=718.6\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ for As${\mathrm{D}}_3$. This information permits the calculation of