On the Spectrum of the P₂ Molecule

Five bands of the ultra-violet system of P 2 , with low v′ and v″ values, have been measured under large dispersion and analysed. They serve to determine much more accurately than heretofore possible the rotational constants B e ″ and α e ″, the moment of inertia I e ″, and the internuclear distance r e ″ of the P 2 molecule in the ground state. The following values have been found: B e ″ = 0.3031 cm. −1 , α e ″ = 0.00138 cm. −1 , I e ″ = 92.36∙10 −40 gm.-cm. 2 , r e ″ = 1.895 10 −8 cm.