Spin-free quantum chemistry. III - Bond functions and the Pauling rules.
Spin-free derivation of Pauling rules for evaluating matrix elements for spin-free Hamiltonian over anti-symmetric Slater bond functions
CHEMICAL BOND↗
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Core and repulsion integrals for Loewdin orthogonalized atomic orbitals in pi-electron systems.
Core integral and electron repulsion integral for 2p-p1 Slater-type orbitals of allyl radical and benzene molecule transformed to Lowdin orthogonalized basis set of atomic orbitals
ORTHOGONAL FUNCTION↗
Generalized Sternheimer potential.
Generalization of Sternheimer potential to include wave functions involving spin in nonfactorable way, exhibiting approximate Hamiltonian
QUANTUM THEORY↗
Bipolar angle averages and two-center, two- particle integrals involving r sub 12.
Bipolar angle averages and two-center two- particle integrals involving separation between two particles
STATISTICAL MECHANICS↗
Intermolecular forces in globular molecules. II.
Intermolecular forces in methyl chloride and benzene calculated using spherical shell central potential theory
POTENTIAL THEORY↗
Various methods of solving a first order perturbation equation.
Undetermined coefficient method compared with confluent hypergeometric functions for solving first order perturbation equation for refractive index of He
FIRST ORDER EQUATION↗
Development and discussion of Pugh's quantum electrodynamics.
Pugh quantum electrodynamics theory development by precise derivation of equation for S matrix, relating Feynman and Pugh vertex terms
Glover, E. M.↗
Kinetics of unimolecular breakdown. VIII - The Lindemann-Hinshelwood mechanism.
Quantum mechanical theory of thermal unimolecular breakdown kinetics of activated molecule in inert host gas based on Lindemann-Hinshelwood mechanism
Levine, R. D.↗
Rotational relaxation in parahydrogen and its mixtures with helium, neon, and argon at 300 deg K.
Ultrasonic‐velocity dispersion measurements have been performed in parahydrogen and its mixtures with helium, neon, and argon, all at 300°K. In each case the experimental dispersion curves can be matched successfully to those calculated under the assumption that the 0–2 rotational transition relaxes separately from the 2–4 and higher‐order terms. For pure pH 2 we find a relaxation time 𝜏 20 of 1.30 × 10 −8 sec for the 2 → 0 transition and a 𝜏 42 of 3.90 × 10 −8 sec for the 4 → 2 transition. Comparison with the quantum‐mechanical theories of Roberts and of Davison for H 2 –H 2 collisions using Morse potentials shows good agreement for 𝜏 20 over the temperature range of 75°–300°K. The Morse‐potential asymmetry parameter yielding the best fit is β = 0.113 for Roberts' calculation and 0.108 for Davison's. It is found that He–pH 2 collisions are more effective than pH 2 –pH 2 in producing the J = 0 to J = 2 transition, but less effective for higher‐order transitions. Collisions of neon with pH 2 are found to be more effective at room temperature for inducing the 0 → 2 and 2 → 4 transitions than either helium or argon.
Leonard M Valley↗
Quantum-mechanical transport equation for atomic systems.
A quantum-mechanical transport equation (QMTE) is derived which should be applicable to a wide range of problems involving the interaction of radiation with atoms or molecules which are also subject to collisions with perturber atoms. The equation follows the time evolution of the macroscopic atomic density matrix elements of atoms located at classical position R and moving with classical velocity v. It is quantum mechanical in the sense that all collision kernels or rates which appear have been obtained from a quantum-mechanical theory and, as such, properly take into account the energy-level variations and velocity changes of the active (emitting or absorbing) atom produced in collisions with perturber atoms. The present formulation is better suited to problems involving high-intensity external fields, such as those encountered in laser physics.
Berman, P. R.↗
Measurement and calculation of the Stark-broadening parameters for the resonance lines of singly ionized calcium and magnesium.
The electron-impact-broadened profiles of the resonance lines of singly ionized calcium and magnesium have been measured using an electromagnetically driven shock tube and a rapid-scanning Fabry-Perot spectrometer. For an electron density of 10 to the 17th power per cu cm and a temperature of 19,000 K, we found the Lorentzian half-width of the Ca+ line to be 0.086 A plus or minus 10% and of the Mg+ line to be 0.044 A plus or minus 10%. Using the quantum-mechanical theory of Barnes and Peach and our semiclassical calculation for the calcium lines, we found that the temperature dependence of the theoretical curves is close to that measured, although both theories predict actual values which are somewhat large.
Jones, W. W.↗
Explicit expressions of the potential and its derivatives at the origin in terms of the scattering data
The quantum mechanical theory of scattering of a particle by a spherically symmetrical potential is presented. As in the inverse scattering problem, the input of the calculation is the scattering and bound-state data, and the output is data on the potential. The results discussed are explicit expressions for the values of the potential and its derivatives at the origin in terms of the scattering and boundstate data. Various methods to obtain these results are outlined. The presentation is aimed at introducing these various approaches. The simplest scattering problem (nonrelativistic S-wave scattering on a holomorphic potential without bound states) is used as the basis for discussion, and technicalities are omitted whenever possible without loss of clarity. A complete compilation is given of the results obtained to date in this field, including the treatment of higher partial waves and the Klein-Gordon and Dirac equations.
Calogero, F.↗
On coherent oscillations of a string.
Vibrations of an elastic string when the separation between the ends varies randomly are studied. The emphasis is on the evolution of the coherent, or ordered, oscillations of the string. Using a perturbation technique borrowed from quantum field theory and the modified Kryloff-Bogoliuboff method, the 'multiple scattering' effect of the random separation between the ends on the linear and nonlinear coherent oscillations are investigated. It is found that due to the random interactions the coherent fundamental oscillation as well as the harmonies are damped. Their frequencies are also modified.
Liu, C. H.↗
Properties of resonance wave functions.
Construction and study of resonance wave functions corresponding to poles of the Green's function for several illustrative models of theoretical interest. Resonance wave functions obtained from the Siegert and Kapur-Peierls definitions of the resonance energies are compared. The comparison especially clarifies the meaning of the normalization constant of the resonance wave functions. It is shown that the wave functions may be considered renormalized in a sense analogous to that of quantum field theory. However, this renormalization is entirely automatic, and the theory has neither ad hoc procedures nor infinite quantities.
More, R. M.↗
Many-particle theory of nuclear systems with application to neutron star matter
The research is reported concerning energy-density relation for the normal state of neutron star matter, and the effects of superfluidity and polarization on neutron star matter. Considering constraints on variation, and the theory of quantum fluids, three methods for calculating the energy-density range are presented. The effects of polarization on neutron star structure, and polarization effects on condensation and superfluid-state energy are discussed.
Chakkalakal, D. A.↗
Study of optimum methods of optical communication
Abstracts are reported relating to the techniques used in the research concerning optical transmission of information. Communication through the turbulent atmosphere, quantum mechanics, and quantum communication theory are discussed along with the results.
Harger, R. O.↗
Electron-impact excitation of O III in the distorted-wave approximation
The 3P - 1D electron-impact excitation cross section within the ground configuration of doubly ionized oxygen is calculated in the distorted-wave approximation. An essential element of the present treatment is that orthogonality is not assumed between core and scattering orbitals of the same angular symmetry. Resonance structures are included through the use of quantum-defect theory. Near threshold the effect of an isolated autoionization resonance in the dominant 2D(0) partial wave is found to be important, in agreement with previous close-coupling results.
Pindzola, M. S.↗
Relativistic astrophysics - The view from Texas in Baltimore /Review/
Recent observational and theoretical work presented at the Tenth Texas Symposium on Relativistic Astrophysics held in Baltimore, Maryland from December 15-19, 1980, is outlined. Areas covered include the theoretical foundations of relativistic astrophysics in general relativity, quantum gravitational theory and the association of grand unification with astronomical and cosmological issues, the cosmic microwave, X-ray, gamma-ray, UV, cosmic ray and gravitational wave backgrounds, the current expansion rate and average mass-energy density of the universe, and mechanisms of galaxy formation. Also discussed are the characteristics of active galaxies and clusters emitting in the gamma-ray and X-ray regions, and compact objects formed from supernova explosions, including pulsars, X-ray-emitting neutron stars, Sco X-1 and SS 433, gamma-ray sources, and X-ray and gamma-ray bursters.
Trimble, V. L.↗