OF THE DISSERTATION New Results for Positron Scattering from Noble Gas Atoms and Diatomic Molecules

The matrix shifts of the H-Xe stretching frequency of noble-gas hydrides, HXeCCH, HXeBr, and HXeI in various noble-gas matrices (in Ne, Ar, Kr, and Xe matrices) are investigated via the hybrid quantum-classical simulations. The order of the H-Xe stretching frequencies is found to be ν(gas) < ν(Ne) < ν(Xe) < ν(Kr) < ν(Ar) for HXeCCH and HXeBr, while it is ν(gas) < ν(Ne) < ν(Xe) < ν(Ar) < ν(Kr) f...

Introduction: In a companion abstract [1], we report evidence for tiny amounts of most likely primordial noble gases with solar-like elemental and isotopic composition admixed to Q-type primordial noble gases in an E chondrite. Here, we discuss possible implications of this finding for terrestrial planet formation. The genetic relation of the noble gases in planetary bodies to those in the Sun,...

Horizontal drilling and hydraulic fracturing have enhanced energy production but raised concerns about drinking-water contamination and other environmental impacts. Identifying the sources and mechanisms of contamination can help improve the environmental and economic sustainability of shale-gas extraction. We analyzed 113 and 20 samples from drinking-water wells overlying the Marcellus and Bar...

The total cross sections for Inelastic collisions between excited sodium and noble gas atoms in their ground states, leading to 2 2 3 P^y2 — — 3 ^3/2 excitation transfer in sodium, have been determined in a series of sensitized fluorescence experiments with pure sodium vapour and its mixtures with noble gases. In the experiments with pure sodium, the sodium vapour pressure was varied over the r...

Dynamics of Strong-Field Laser-Induced Micro-Plasma Formation in Noble Gases D. A. Romanov, R. Compton, A. Filin, R. J. Levis 1. Center for Advanced Photonics Research, College of Science and Technology Temple University, Philadelphia, PA 19122 2. Department of Physics, Temple University, Philadelphia, PA 19122 3. Department of Chemistry, Temple University, Philadelphia, PA 19122 (Physical Revi...

The utility of noble gases for phase determination has been limited by the lack of naturally occurring binding sites in proteins. Wild-type T4 lysozyme contains one such binding site. By mutating large hydrophobic residues to alanine, additional noble-gas binding sites have been successfully introduced into this protein. Using data from xenon derivatives of the wild type, two single mutants and...

We discuss the present status and reliability of theoretical predictions of noble-gas hydride molecules. It is shown that the single-reference MP2 calculations can produce a rather inaccurate energy diagram for the formation of noble-gas hydrides, and this may mislead the theoretical predictions. We suggest that the computational dissociation energy of the HY precursors should always be compare...

The Fermi-contact interaction that characterizes collisional spin exchange of a noble gas with an alkali-metal vapor also gives rise to NMR and EPR frequency shifts of the noble-gas nucleus and the alkali-metal atom, respectively. We have measured the enhancement factor κ0 that characterizes these shifts for Rb-129Xe to be 493±31, making use of the previously measured value of κ0 for Rb-3He. Th...

We present calculations at the relativistic coupled cluster theory that predict the (1)Sigma(0) (+) ground state of CUO to lie 58.2 kJ/mol below the first excited state, (3)Phi(2). This can be contrasted with the outcome of earlier density functional theory and complete active space second order perturbation theory (CASPT2) calculations that both predicted a (3)Phi(2) ground state upon inclusio...