Explicit HilbertSpace Representations of Atomic and Molecular Photoabsorption Spectra.
Abstract
Explicit Hilbertspace techniques are reported for construction of the discrete and continuum Schrodinger states required in atomic and molecular photoexcitation and photoionization studies. These developments extend and clarify momenttheory methods for determinations of photoabsorption cross section from discrete basis set calculations to include explicit construction of the underlying wavefunctions. So called StieltjesTchebycheff wavefunctions are constructed in a CauchyLanczos basis and shown to provide convergent L('2) approximations to the exact Schrodinger solution at any energy in the spectrum. Connections with matrix partitioning methods indicate StieltjesTchebycheff wavefunctions are optical potential solutions of the matrix Schrodinger equation in the full CauchyLanczos basis. StieltjesTchebycheff wavefunctions can be constructed in molecular point group symmetry and, consequently, are applicable to studies of absorption and ionization in diatomic and polyatomic molecules. Analysis of bound and continuum wavefunctions using 3dimensional plots and molecular orbital techniques provide useful diagnostics of strong resonance features seen in both discrete and continuum regions of measured photoabsorption cross sections. Electronically and vibrationally resolved photoabsorption studies are reported for the stable gas phase compounds N(,2), H(,2), NO, and N(,2)O using the StieltjesTchebycheff techniques. These studies provide a basis for analyzing and understanding measured photoabsorption cross sections relevant to aeronomy and astrophysics.
 Publication:

Ph.D. Thesis
 Pub Date:
 1984
 Bibcode:
 1984PhDT........99H
 Keywords:

 Physics: Molecular