A5054240325- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Origins and Evolution of Life
- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Molecular spectroscopy and chirality
- Quantum Mechanics and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Astro and Planetary Science
- Quantum, superfluid, helium dynamics
- Magnetism in coordination complexes
- Quantum and Classical Electrodynamics
- Advanced Physical and Chemical Molecular Interactions
- Quantum optics and atomic interactions
- Muon and positron interactions and applications
- Atmospheric Ozone and Climate
- Atomic and Subatomic Physics Research
- Spectroscopy and Laser Applications
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- Planetary Science and Exploration
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- Scientific Measurement and Uncertainty Evaluation
Wake Forest University
1986-2011
University of Houston - Clear Lake
2004
University of Oxford
1979
Pennsylvania State University
1971-1973
Harvard University
1966-1969
The theory of energy shifts in mirror-image molecules arising from parity nonconserving weak neutral currents is developed. Its connection with the optical activity discussed. In order to demonstrate existence shift, which produces an difference between optically active molecule and its mirror image, exact calculation performed for a simple one-electron model (the Condon model). Then approximate LCAO-MO calculations are on two specific molecules, twisted ethylene A-nor-2-thiacholestane,...
The interaction of hydrogenic atoms with a weak constant magnetic field is discussed in detail. Breit Hamiltonian, minimally coupled to the external field, treated several different ways. First, approximate eigenfunctions are obtained nonrelativistic nucleus approximation. These wave functions used treat perturbatively residual terms dependent on and identify moment bound electron ground state. corrections previously given by us, relative order ${(Z\ensuremath{\alpha})}^{2}$,...
The unusual magnetic properties of the 1Σ+ BH molecule calculated earlier from perturbed (coupled) Hartree—Fock theory have been confirmed, and rendered more nearly gauge invariant. Predictions spin—rotation constant for hydrogen are CH=−14.9 kc/sec with B as origin, CH=−18.2 H compared values −8.5 −25.3 kc/sec, respectively. Also, shielding at is σH=24.46 ppm origin σH=25.44 our previous 22.55 27.62 ppm, In addition, we present an interpretation molecular paramagnetism, antishielding B,...
The Hamiltonian for a many-particle system in homogeneous magnetic field is constructed by straightforward extension of previous work on hydrogenic atoms Grotch and Hegstrom. Relativistic-correction terms order ${\ensuremath{\alpha}}^{2}{\ensuremath{\mu}}_{B}H$ are identical to those obtained many years ago Abragam Van Vleck Perl Hughes. In addition, higher-order due the anomalous moments nuclear motion explicitly formulated present work. These orders...
Proofs that closed-shell molecules must be diamagnetic are shown to restricted two-electron systems. An exact nonrelativistic ground-state wave function having four or more electrons is possess a nodal structure which arises from the Pauli principle. These nodes cause proofs molecular necessarily invalid when than one pair of present. The physical situation examined with special reference diatomic BH molecule.
It is calculated that an unpolarized electron beam elastically scattered from a chiral molecule will acquire net helicity of $H(s)\ensuremath{\sim}\ensuremath{\eta}{(\ensuremath{\alpha}Z)}^{2}$, where $\ensuremath{\alpha}=\frac{{e}^{2}}{\ensuremath{\hbar}c}$, $Z$ the atomic number heaviest atom in asymmetric environment molecule, and $\ensuremath{\eta}$ molecular asymmetry factor. For carbon center ($Z=6$), estimated to be ${10}^{\ensuremath{-}2}$ so...
A theoretical framework is presented from which precise electronic $g$ values for molecules may be calculated. The theory applied to the calculation of factors and related magnetic properties ${\mathrm{H}}_{2}^{+}$, H${\mathrm{D}}^{+}$, ${\mathrm{D}}_{2}^{+}$. average value ground state each these molecular ions predicted shifted by about 3 ppm factor atomic hydrogen. results are expected accurate 0.1 ppm, when compared with future experimental measurements provide first test factors.
Values of magnetic constants for the 11B 19F molecule in its 1Σ+ ground state have been calculated ab initio using coupled Hartree-Fock perturbation theory. Predicted values, average two calculations employing different gauge origins, are χ = − 14.3 ppm, μj /J 0.21 nm, σF 250 CF 85.7 kc / sec, σB 82.9 and CB 15.8 sec. anisotropies BF Δχ 5.92 ΔσF 360.6 ΔσB 188.2 ppm. In addition, values BH to be 45.80 690.9 ΔσH 12.53
Atoms are chiral due to the parity-violating weak neutral current interaction between nucleus and electrons. A simple pictorial representation of chirality an atom is obtained by mapping electron probability density in atom. Results shown for a hydrogenic 2p1/2 stationary state.
Bound-state relativistic contributions to the ${g}_{J}$ factor of ground-state atomic lithium are calculated and compared with experimental value $\frac{{g}_{J}(\mathrm{Li})}{{g}_{e}}=1\ensuremath{-}(8.9\ifmmode\pm\else\textpm\fi{}0.4)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, where ${g}_{e}$ is free-electron $g$ factor. This comparison taken as basis for judging accuracy several different Li wave functions from literature. Most these give agreement within uncertainty. A more...
The Breit equation for two Dirac particles in an external magnetic field, with anomalous moments introduced phenomenologically as Pauli moments, is taken the starting point a Chraplyvy-Barker-Glover reduction. First-order perturbation theory employing nonrelativistic wave function $^{2}S$ ground state then used to derive expressions diagonal matrix elements of Hamiltonian which depend linearly upon field. These are symmetric masses and agree previous results relative order...
An LCAO SCF wavefunction for BH4− has been optimized with respect to variation of orbital exponents in a minimum basis set. The resulting charge distribution, quite different from that given by Slater exponents, yields Mulliken charges +0.044 B and −0.261 each H atom. These results, electron density maps, indicate the unit negative is distributed among four atoms, which have an exponent 1.04.
Starting from coupled Hartree—Fock perturbation theory, approximate expressions are derived for the magnetic shielding of a nucleus in field. Some these compared with existent formulas which have been by other methods. The concept localized contributions is explored and illustrated case diatomic molecules LiH BH, exact calculations performed.
The ${g}_{J}$ factor for the excited $2^{3}S_{1}$ state of helium has been calculated from a generalized Breit equation which includes radiative corrections. result is $(\mathrm{He},2^{3}S_{1})={g}_{e}(1\ensuremath{-}40.91640\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6})=\ensuremath{-}2.002237379$. This in good agreement with previous theoretical value by Perl and Hughes to order ${\ensuremath{\alpha}}^{2}$. Higher-order corrections (${\ensuremath{\alpha}}^{3} \mathrm{and}...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical Shifts of Boron-11 in Icosahedral CarboranesR. A. Hegstrom, M. D. Newton, J. Potenza, and W. N. LipscombCite this: Am. Chem. Soc. 1966, 88, 22, 5340–5342Publication Date (Print):November 1, 1966Publication History Published online1 May 2002Published inissue 1 November 1966https://pubs.acs.org/doi/10.1021/ja00974a066https://doi.org/10.1021/ja00974a066research-articleACS PublicationsRequest reuse permissionsArticle...