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Extended virial theorem applied to predissociation phenomena. Interpretation of the nearly degenerate G 1 Π ∼ I 1 Π energy spectra in SiO
Author(s) -
Brändas Erkki,
Elander Nils,
Froelich Piotr
Publication year - 1978
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560140410
Subject(s) - degenerate energy levels , virial theorem , spectral line , virial coefficient , laplace transform , quantum mechanics , virial expansion , interpretation (philosophy) , physics , atomic physics , chemistry , mathematics , mathematical analysis , galaxy , computer science , programming language
The extended virial theorem, obtained from a Fourier–Laplace transformation of equations of motion, is applied to the phenomenon of predissociation. The underlying resonance energy model rigorously defined by means of the theory of dilation analytic operators prescribes in detail the balance between the various energy contributions in a way analogous to the situation prevailing in a stationary system. The extended virial theorem is applied to predissociation, particularly in connection with the interpretation of the nearly degenerate G 1 Π ∼ I 1 Π energy spectrum in SiO. It was previously found for the rovibronic spectra assigned to G 1 Π – X 1 Σ + and I 1 Π – X 1 Σ + , that every G – X band is accompanied by a I – X band. Whereas the I 1 Π state does not seem to undergo predissociation, the G state shows increasing predissociation with increasing vibrational quantum number. We show that the virial theorem generalized to include continuum phenomena offers an interpretation of the nearly degenerate spectra of SiO as well as of the concomitant isotope shift of SiO 16 and SiO 18 with respect to both resonance positions and widths.