The Spectrum of AsO

The band-heads of two systems due to AsO have been measured, and the following equations deduced as the best representation of the vibrational structure $\{A: \nu =,\{31,655.8\}\{30,631.1\}+683.8(v^{\prime }+\frac{1}{2})-9.42\mathrm{}{(v^{\prime }+\frac{1}{2})}^2-966.6(v^{\prime \prime }+\frac{1}{2})+4.92\mathrm{}{(v^{\prime \prime }+\frac{1}{2})}^2\}\{B: \nu =,\{39,862.0\}\{38,838.3\}+1098(v^{\prime }+\frac{1}{2})-6\mathrm{}{(v^{\prime }+\frac{1}{2})}^2-966.6(v^{\prime \prime }+\frac{1}{2})+4.92\mathrm{}{(v^{\prime \prime }+\frac{1}{2})}^2.\}$ The intensity distribution in system $A$ is normal, but in system $B$ the $v^{\prime }=0\mathrm{}$ progression is predominant. This is explained by predissociation, and a value of 4.93 volts is found for the heat of dissociation of AsO.