Predissociation spectrum of an excited electronic state of theH3molecule

The structure recently observed by Vogler in the dissociation spectrum of the ${\mathrm{H}}_3$ molecule is attributed to the predissociation of the $2s{}_{}{}^2{}_{}{}^{}A_1^{}{}_{}{}^{\prime }$ electronic state of ${\mathrm{H}}_3$ to H atoms and various vibration-rotation levels of the ground electronic state of ${\mathrm{H}}_2$. The process ${\mathrm{H}}_3(2s{}_{}{}^2{}_{}{}^{}A_1^{}{}_{}{}^{\prime },v=0)\to {\mathrm{H}}_2(X{}_{}{}^1{}_{}{}^{}\Sigma _g^{+}{}_{}{}^{},v=J=0)+\mathrm{H}\left(1s{}_{}{}^2{}_{}{}^{}S\right)$ is found to be exothermic by 5.52 eV.