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Full-Text Articles in Physics

Photoelectron Angular Distributions From Rotationally Resolved Autoionizing States Of N2, Alexander M. Chartrand, Elizabeth F. Mccormack, Ugo Jacovella, David M P Holland, Berenger Gans, Xiaofeng Tang, Gustavo A. García, Laurent Nahon, Stephen T. Pratt Dec 2017

Photoelectron Angular Distributions From Rotationally Resolved Autoionizing States Of N2, Alexander M. Chartrand, Elizabeth F. Mccormack, Ugo Jacovella, David M P Holland, Berenger Gans, Xiaofeng Tang, Gustavo A. García, Laurent Nahon, Stephen T. Pratt

Physics Faculty Research and Scholarship

The single-photon, photoelectron-photoion coincidence spectrum of N2 has been recorded at high (~1.5 cm–1 ) resolution in the region between the N2+ X 2Σg+, v+ = 0 and 1 ionization thresholds by using a double-imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the N2+ X 2 …


Continuity Of Heavy Rydberg Behaviour In The Ungerade Ion-Pair States Of H2, Alexander M. Chartrand, Robert J. Donovan, Kenneth P. Lawley, Elizabeth Mccormack May 2017

Continuity Of Heavy Rydberg Behaviour In The Ungerade Ion-Pair States Of H2, Alexander M. Chartrand, Robert J. Donovan, Kenneth P. Lawley, Elizabeth Mccormack

Physics Faculty Research and Scholarship

Heavy Rydberg behaviour and absolute quantum defects are reported for resonances in the ungerade manifold of H2 above the (1s, 3l) dissociation limit. The continuity of the vibrational progression of the B''B-bar state through the crossing with the 3p asymptote is demonstrated and a predominantly diabatic picture of the vibrational motion emerges, indicating that the ion-pair resonances possess little 61Σu+ state character.


Solid Solid Phase Transitions And Tert-Butyl And Methyl Group Rotation In An Organic Solid: X-Ray Diffractometry, Differential Scanning Calorimetry, And Solid-State H-1 Nuclear Spin Relaxation, Peter A. Beckmann, Andrew R. Mcghie, Arnold L. Rheingold, Gilbert J. Sloan, Steven T. Szewczyk Jan 2017

Solid Solid Phase Transitions And Tert-Butyl And Methyl Group Rotation In An Organic Solid: X-Ray Diffractometry, Differential Scanning Calorimetry, And Solid-State H-1 Nuclear Spin Relaxation, Peter A. Beckmann, Andrew R. Mcghie, Arnold L. Rheingold, Gilbert J. Sloan, Steven T. Szewczyk

Physics Faculty Research and Scholarship

Using solid state 1H nuclear magnetic resonance (NMR) spin-lattice relaxation experiments, we have investigated the effects of several solid-solid phase transitions on t-butyl group and methyl group rotation in solid 1,3,5-tri-t-butylbenzene. The goal is to relate the dynamics of the t-butyl groups and their constituent methyl groups to properties of the solid determined using single-crystal X-ray diffraction and differential scanning calorimetry (DSC). On cooling, the DSC experiments see a first-order, solid-solid phase transition at either 268 K or 155 K (but not both) depending on thermal history. The 155 K transition (on cooling) is identified by …


Monitoring A Simple Hydrolysis Process In An Organic Solid By Observing Methyl Group Rotation, Peter A. Beckmann, Joseph M. Bohen, Jamie Ford, William P. Malachowski, Clelia W. Mallory, Frank B. Mallory, Andrew R. Mcghie, Arnold L. Rheingold, Gilbert J. Sloan, Steven T. Szewczyk, Xianlong Wang, Kraig A. Wheeler Jan 2017

Monitoring A Simple Hydrolysis Process In An Organic Solid By Observing Methyl Group Rotation, Peter A. Beckmann, Joseph M. Bohen, Jamie Ford, William P. Malachowski, Clelia W. Mallory, Frank B. Mallory, Andrew R. Mcghie, Arnold L. Rheingold, Gilbert J. Sloan, Steven T. Szewczyk, Xianlong Wang, Kraig A. Wheeler

Physics Faculty Research and Scholarship

We report a variety of experiments and calculations and their interpretations regarding methyl group (CH3) rotation in samples of pure 3-methylglutaric anhydride (1), pure 3-methylglutaric acid (2), and samples where the anhydride is slowly absorbing water from the air and converting to the acid [C6H8O3(1) + H2O → C6H10O4(2)]. The techniques are solid state 1H nuclear magnetic resonance (NMR) spin-lattice relaxation, single-crystal X-ray diffraction, electronic structure calculations in both isolated molecules and in clusters of molecules that mimic the crystal structure, field emission scanning electron microscopy, differential scanning calorimetry, and high resolution …


An Approximate Analytic Model Of A Star Cluster With Potential Escapers, Kathryne J. Daniel, Douglas C. Heggie, Anna Lisa Varri Jan 2017

An Approximate Analytic Model Of A Star Cluster With Potential Escapers, Kathryne J. Daniel, Douglas C. Heggie, Anna Lisa Varri

Physics Faculty Research and Scholarship

In the context of a star cluster moving on a circular galactic orbit, a “potential escaper” is a cluster star that has orbital energy greater than the escape energy, and yet is confined within the Jacobi radius of the stellar system. On the other hand analytic models of stellar clusters typically have a truncation energy equal to the cluster escape energy, and therefore explicitly exclude these energetically unbound stars. Starting from the landmark analysis performed by Hénon of periodic orbits of the circular Hill equations, we present a numerical exploration of the population of “non-escapers”, defined here as those stars …