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in subjects: "Hartree-Fock Method"

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General multi-configuration Hartree--Fock program: MCHF77. [In FORTRAN (double precision) for IBM 360 and 370]

This technical report contains a listing of a general program for multi-configuration Hartree--Fock (MCHF) calculations, including its documentation. Several examples are given showing how the program may be used. Typical output for several cases is also presented. This program has been tested over an extended period of time for a large variety of cases. This program is written for the IBM 360 or 370 in double-precision arithmetic.

Date: November 1, 1977

Creator: Fischer, C F

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Application of the graphical unitary group approach to the energy second derivative for CI wave functions via the coupled perturbed CI equations

Analytic derivatives of the potential energy for Self-Consistent-Field (SCF) wave functions have been developed in recent years and found to be useful tools. The first derivative for configuration interaction (CI) wave functions is also available. This work details the extension of analytic methods to energy second derivatives for CI wave functions. The principal extension required for second derivatives is evaluation of the first order change in the CI wave function with respect to a nuclear p… more

Date: October 1, 1983

Creator: Fox, D.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Angular distributions of photoelectrons and non-thermal photoions from atoms and molecules. [Review]

During the last ten years, photoelectron angular distributions have been used extensively to study the dynamics of the photoionization process in atoms and molecules. Some major advances in this body of work are reviewed with special emphasis on results emerging since the last Conference on VUV Radiation Physics three years ago. By far the greatest progress has occurred for atoms, where interest is focussed on improving zero-order (Hartree-Slater, Cooper-Zare) understanding of the asymmetry par… more

Date: January 1, 1977

Creator: Dehmer, J. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mound Facility activities in chemical and physical research: July-December 1979

Research is reported in the following fields: isotope separation (Ar, C, He, Kr, Ne, O, Xe), low-temperature research (H intermolecular potential functions, gas analysis in trennschaukel), separation chemistry (/sup 229/Th, /sup 231/Pa, /sup 230/Th, /sup 234/U), separation research (liquid thermal diffusion, Ca isotope separation, molecular beam scattering, mutual diffusion of noble gas mixtures, lithium chemical exchange with cryptands), and calculations in plutonium chemistry (algorithms, val… more

Date: June 18, 1980

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Science and art in heavy-ion collisions

One of the more intriguing phenomena discovered in heavy-ion physics is the seeming appearance of high energy structure in the excitation spectra of inelastically scattered heavy ions. For reasons illustrated, these may well be a phenomena unique to heavy ions and their explanation perhaps unique to TDHF.

Date: August 9, 1982

Creator: Weiss, M.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Constant <H> resolution of time-dependent Hartree--Fock phase ambiguity

The customary time-dependent Hartree--Fock problem is shown to be ambiguous up to an arbitrary function of time additive to H/sub HF/, and, consequently, up to an arbitrary time-dependent phase for the solution, PHI(t). The ''constant'' (H)'' phase is proposed as the best resolution of this ambiguity. It leads to the following attractive features: (a) the time-dependent Hartree--Fock (TDHF) Hamiltonian, H/sub HF/, becomes a quantity whose expectation value is equal… more

Date: January 1, 1978

Creator: Lichtner, P. C.; Griffin, J. J.; Schultheis, H.; Schultheis, R. & Volkov, A. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Mayer-Fermi Theory and the Long Sequences in the Periodic Table

Changes in the radial wave functions for d electrons which occur preceding the onset of the transition series of elements and for f electrons preceding the onset of the lanthanide and actinide series are examined. The sensitivity of the radial wave functions to variations in the effective potential is discussed, and the large variation in the radial wave functions between the LS terms of certain types of excited configurations in these regions of the periodic system is analyzed. Several example… more

Date: January 1, 1986

Creator: Griffin, D. C.; Cowan, R. D. & Pindzola, M. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Heavy ion scattering in 3D TDHF. [Isodensity contours]

Results of three-dimensional (3D) time-dependent Hartree--Fock (TDHF) calculations are presented. The assumptions used in the calculations are summarized. The first reaction considered is /sup 16/O + /sup 16/O at 105 MeV (lab); isodensity contours integrated perpendicular to the reaction plane are shown for several impact parameters as a function of time. Trajectories are also shown, and the kinetics of the reaction is discussed; several other energies were also examined. Most of the deeply ine… more

Date: September 1, 1977

Creator: Weiss, M.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ab initio effective core potentials including relativistic effects and their application to the electronic structure calculations of heavy atoms and molecules

The effects of the 4f shell of electrons and the relativity of valence electrons are compared. The effect of 4f shell (lanthanide contraction) is estimated from the numerical Hartree-Fock (HF) calculations of pseudo-atoms corresponding to Hf, Re, Au, Hg, Tl, Pb and Bi without 4f electrons and with atomic numbers reduced by 14. The relativistic effect estimated from the numerical Dirac-Hartree-Fock (DHF) calculations of those atoms is comparable in the magnitude with that of the 4f shell of elec… more

Date: November 1, 1977

Creator: Lee, Y. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pion Condensation in a Field Theory Consistent with Bulk Properties of Nuclear Matter

No Description Available.

Date: May 1, 1980

Creator: Banerjee, B.; Glendenning, N.K. & Gyulassy, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electronic structure of molecules using relativistic effective core potentials

Starting with one-component Cowan-Griffin relativistic Hartree-Fock orbitals, which successfully incorporate the mass-velocity and Darwin terms present in more complicated wavefunctions such as Dirac-Hartree-Fock, one can derive relativistic effective core potentials (RECP's) to carry out molecular calculations. These potentials implicitly include the dominant relativistic terms for molecules while allowing one to use the traditional quantum chemical techniques for studying the electronic struc… more

Date: January 1, 1981

Creator: Hay, P.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Incorporation of particle collisions in the time-dependent Hartree-Fock approximation

In the time-dependent Hartree-Fock (TDHF) approximation, particles interact only through the mean field, and the collisions between particles are not included. Previously, we formulated the extended time-dependent Hartree-Fock (ETDHF) approximation to include particle collisions in terms of a temporal variation of the occupation probability n/sub lambda/ for the single-particle states. In the simplest approximation, the single-particle potential is modified only through the particle density whi… more

Date: January 1, 1982

Creator: Wong, C.Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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TDHF for heavy ions

The main consequences of the TDHF approximation are discussed and the present status of comparison with experimental data. It is intended that this will help to answer the question of whether the results obtained from the method are in reasonable proportion to the effort invested. 27 references. (JFP)

Date: January 1, 1979

Creator: Maruhn, J.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Shape isomers as candidates for the gamma ray laser storage state

Three Dimension Nuclear Hartree-Fock calculations have been performed for isotopes of Osmium, Mercury, and Tungsten. Many of the calculated potential energy surfaces show a second minimum at large prolate deformation indicating the possibility of shape isomeric states. Several are at sufficiently low energy to be possible candidates as storage states for the gamma ray laser. 9 refs., 4 figs., 1 tab.

Date: December 1, 1987

Creator: Weiss, M.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Why linear Birch and U/sub s/-U/sub p/ expansions work

The equivalence of the Birch-Murnaghan equation to a linear U/sub s/-U/sub p/ equation was illustrated in the previous paper. Here we show in a direct manner how the virial theorem and the effect of core exclusion on valence electron kinetic energy changes lead to the convergence of the Eulerian strain expansion about the zero-pressure state. 7 refs., 4 tabs.

Date: November 1, 1987

Creator: Grover, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Numerical simulations of multiphoton processes in many electron atoms

In this report, we will present some details of two numerical methods which we have been pursuing for treating the multi-electron case. Both involve a numerical representation of the time dependent Hartree Fock electronic orbitals and a direct time integration of the coupled equations. Using these methods we will be able to determine the dynamics of the energy absorption process (preionization dynamics and the mechanism of ionization, i.e. whether it is direct multi-electron emission or sequent… more

Date: September 1, 1987

Creator: Kulander, K.C. & Cerjan, C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Time-dependent Hartree--Fock theory: application to the /sup 14/N + /sup 12/C reaction

The results obtained from a pure time-dependent Hartree-Fock calculation of the /sup 14/N + /sup 12/C reaction are used as the basis for further investigations designed to overcome shortcomings of the theory and leading to suggestions for further development of this theory itself. It is shown that the studied theory does indeed provide a basic first step towards a more detailed theory of heavy-ion reactions. Among the parameters considered are the classical deflection function, kinetic energy l… more

Date: January 1, 1977

Creator: Maruhn, J.A.; Cusson, R.Y. & Meldner, H.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Energy levels and lifetimes of 2P/sup 5/3S3D quartets in Na I

The 2p/sup 5/3s3d/sup 4/L levels in NAI can decay in three ways: El transitions to 2p/sup 5/3s3p levels (/sup 4/L allowed), El transitions to 2p/sup 6/Nl/sup 2/L (spin forbidden), and autoionization to 2p/sup 6/Kl/sup 2/L (spin-forbidden). Multi-configuration Hartree-Fock calculations with Breit-Pauli corrections were preformed for each mode of decay with special emphasis given to the 2p/sup 5/3s3p/sup 4/L - 2p/sup 5/3s3d/sup 4/L transitions. 3 refs., 4 tabs.

Date: January 1, 1986

Creator: Fischer, C. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electron impact ionization of heavy ions: some surprises

This paper reports the results of calculations of electron impact ionization cross sections for a variety of heavy ions using a distorted wave Born-exchange approximation. The target is described by a Hartree-Fock wavefunction. The scattering matrix element is represented by a triple partial wave expansion over incident, scattered, and ejected (originally bound) continuum states. These partial waves are computed in the potentials associated with the initial target (incident and scattered waves)… more

Date: August 22, 1986

Creator: Younger, S.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Theoretical energy levels of /sup 3/F/sup 0/ Rydberg series for Mg I, Al II, and Si III. [Multiconfiguration Hartree-Fock]

A multiconfiguration Hartree-Fock procedure for excited states is described and applied to states of the Rydberg series up to 3s 8f /sup 3/F/sup 0/ in Mg I, Al II, and Si III. Energies relative to the ionization limit agree with observation to within 1%, an exception being the case of near-degeneracy in Al II, where a discrepancy of 2.5% occurs. Systematic errors are observed. Some possible sources of errors are considered. 2 figures, 6 tables.

Date: January 1, 1979

Creator: Fischer, C F

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Zero temperature quark matter equation of state

An equation of state is computed for a plasma of one flavor quarks interacting through some phenomenological potential, in the Hartree approximation, at zero temperature. Assuming that the confining potential is scalar and color-independent, it is shown that the quarks undergo a first-order mass phase transition. In addition, due to the way screening is introduced, all the thermodynamic quantities computed are independent of the actual shape of the interquark potential. This equation of state i… more

Date: September 1, 1987

Creator: Grassi, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Time independent mean-field theory

The physical and theoretical motivations for the time-dependent mean-field theory are presented, and the successes and limitations of the time-dependent Hartree-Fock initial-vaue problem are reviewed. New theoretical developments are described in the treatment of two-body correlations and the formulation of a quantum mean-field theory of large-amplitude collective motion and tunneling decay. Finally, the mean-field theory is used to obtain new insights into the phenomenon of pion condensation i… more

Date: February 1, 1980

Creator: Negele, J.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Time-dependent variational principle for quantum dynamics in the Schrodinger-picture

Starting with the exact variational formulation of quantum mechanics (or quantum field theory) in the Schroedinger picture, and using Gaussian trail wave functions, an exact functional Schroedinger equation is obtained. The time-dependent Hartree-Fock approximation is obtained and extended to many oscillators and to field theory. The problem of quantum roll, in which an initial Gaussian wave packet starting at an unstable classical equilibrium point evolves in time, is treated using this formal… more

Date: January 1, 1986

Creator: Cooper, F. & Pi, S.Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Programmability of the HPCS Languages: A Case Study with a Quantum Chemistry Kernel (Extended Version)

As high-end computer systems present users with rapidly increasing numbers of processors, possibly also incorporating attached co-processors, programmers are increasingly challenged to express the necessary levels of concurrency with the dominant parallel programming model, Fortran+MPI+OpenMP (or minor variations). In this paper, we examine the languages developed under the DARPA High-Productivity Computing Systems (HPCS) program (Chapel, Fortress, and X10) as representatives of a different par… more

Date: April 1, 2008

Creator: Shet, Aniruddha G; Elwasif, Wael R; Harrison, Robert J & Bernholdt, David E

Item Type: Report

Partner: UNT Libraries Government Documents Department