We present an analysis of the pairing resonances observed in photo-double-ionization studies of CnHm aromatic molecules with multiple benzene-like rings. The analysis, which is based on the Coulomb pairing model, is applied to naphthalene, anthracene
, phenanthrene, pyrene and coronene, all of which have six-member rings, and azulene which is comprised of a five-member and a seven-member ring. There is a high energy resonance at ~ 40 eV that is found in all of the molecules cited and is associated with paired electrons localized on carbon sites on the perimeter of the molecule, each of which having two carbon sites as nearest neighbors. The low energy resonance at 10 eV, which is found only in pyrene and coronene, is attributed to the formation of paired electrons localized on arrays of interior carbon atoms that have the point symmetry of the molecule with each carbon atom having three nearest neighbors. The origin of the anomalous increase in the doubly charged to singly charged parent-ion ratio that is found above the 40 eV resonance in all of the cited molecules except coronene is discussed.
The purpose of this note is to connect early work on thermal transport in spin-1/2 Heisenberg chains with uniaxial exchange anisotropy and nearest-neighbor interactions that was based on a moment analysis of the Fourier transform of the energy densit
y correlation function with subsequent studies that make use of thermal current correlation functions.
Partial Quantum Nearest Neighbor Probability Density Functions (PQNNPDFs) are formulated for the purpose of determining the behavior of quantum mixed systems in equilibrium in a manner analogous to that provided for classical multi-component systems.
Developments in partial quantum m-tuplet distribution functions, a generalization of the partial quantum radial distribution function, along with their relationship to PQNNPDFs, are briefly elucidated. The calculation of statistical thermodynamic properties of quantum mixtures is presented for arbitrary material systems. Application to the limiting case of dilute, weakly correlated quantum gas mixtures has been outlined and the second virial coefficient is derived. The case of dilute strongly degenerate mixtures is also addressed, providing an expression for the PQNNPDF applicable in this thermodynamic regime.
