Spectrum of the HD- and D₂-Molecules

Abstract

WE have photographed the molecular spectrum of hydrogen under high dispersion and obtained a series of photographs of samples with increasing amounts of the heavy isotope ranging from pure H₂ to practically pure D₂. We are indebted to Prof. H. S. Taylor, of Princeton, for the heavy hydrogen. In this way it was possible to decide unambiguously whether a line is due to H₂, HD or D₂. It is well known that a considerable part of the H₂-spectrum was analysed chiefly through the efforts of O. W. Richardson and his co-workers, but there remains a great number of problems concerned with the analysis and interpretation of this complicated spectrum. The main purpose of the present investigation is to obtain additional material which can be used for a further analysis of the molecular spectrum of hydrogen and to help to clear up doubtful points in its interpretation. We are confident that in this way our knowledge of the structure of the hydrogen molecule can be greatly increased.