The absorption spectrum of solid oxygen in the wavelength region from 12,000 Å to 3300 Å

Abstract

The electronic absorption band systems of oxygen with upper states 1Δg, 1Σg+, 1Δg + 1Δg, 1Δg + 1Σg+ and 1Σg + 1Σg+ were investigated in detail in the a form of the solid (~21°K); some data were obtained also for the β and γ modifications. Although the nineteen bands of α-O2 studied exhibit great diversity in structure, the profiles show in general a rather sharp red edge and intensity degradation towards the violet. The over-all structure of each band is interpreted as the superposition of combination tones of the appropriate molecular frequency vm with continuous distributions of lattice frequencies; each distribution is more or less sharply peaked at v = vm + nvD (n = 0, 1, 2, ⋯), where vD is the Debye frequency of the solid. The main component of the 0-0 band of each system corresponds to double phonon creation (n = 2); for the higher members of each vibrational progression, single phonon creation (n = 1) is more probable. Most of the subsidiary maxima correspond to less probable phonon transitions, i.e. with n not equal to the most probable value. The molecular constants (Te', ωe',xe', ωe') derived from the analysis depart very little from the values for the free molecule.