Spin-polarized hydrogen, deuterium, and tritium: II. Pressure and compressibility calculated by a lowest order constrained-variation method

1989 ◽  
Vol 67 (7) ◽  
pp. 649-656 ◽  
Author(s):  
Magne Haugen ◽  
Erlend Østgaard
Keyword(s):  
Molar Volume ◽  
Ground State ◽  
Particle Density ◽  
Variation Method ◽  
Density Region ◽  
Spin Polarized ◽  
Hydrogen Deuterium ◽  
Constrained Variation ◽  
Ground State Energies ◽  
Theoretical Results

The pressure and the compressibility of spin-polarized H↓, D↓, and T↓ are obtained from ground-state energies calculated by means of a modified variational lowest order constrained-variation method. The pressure and the compressibility are calculated or estimated from the dependence of the ground-state energy on density or molar volume, generally in a density region from 0 to 1.5σ−3 corresponding to a molar volume of more than 20 cm3/mol, where σ = 3.69 Å (1Å = 10−10 m); the calculations are done for five different two-body potentials. Theoretical results for the pressure are 54.1–57.9 atm for spin-polarized H↓ 18.4–23.4 atm for spin-plolarized D↓, and 5.6–12.9 atm for spin-polarized T↓ at a particle density of 0.50σ−3 or a molar volume of 60 cm3/mol (1 atm = 101 kPa). Theoretical results for the compressibility are 51 × 10−4 −54 × 10−4 atm−1 for spin-polarized H↓, 108 × 10−4 −120 × 10−4 atm−1 for spin-polarized D↓, and 162 × 10−4 −224 × 10−4 atm−1 for spin-polarized T↓ at a particle density of 0.50σ−3 for a molar volume of 60 cm3/mol. The relative agreement between results for different potentials is somewhat better for higher densities.

Spin-polarized hydrogen, deuterium, and tritium: I. Ground-state energy calculated by a lowest order constrained-variation method

1989 ◽  
Vol 67 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Magne Haugen ◽  
Erlend Østgaard
Keyword(s):  
Binding Energy ◽  
Molar Volume ◽  
Ground State ◽  
Particle Density ◽  
Variation Method ◽  
Ground State Binding Energy ◽  
Spin Polarized ◽  
Hydrogen Deuterium ◽  
Constrained Variation ◽  
Theoretical Results

The ground-state energy of spin-polarized hydrogen, deuterium, and tritium is calculated by means of a modified variational lowest order constrained-variation method, and the calculations are done for five different two-body potentials. Spin-polarized H↓ is not self-bound according to our theoretical results for the ground-state binding energy. For spin-polarized D↓, however, we obtain theoretical results for the ground-state binding energy per particle from −0.42 K at an equilibrium particle density of 0.25 σ−3 or a molar volume of 121 cm3/mol to + 0.32 K at an equilibrium particle density of 0.21 σ−3 or a molar volume of 142 cm3/mol, where σ = 3.69 Å (1 Å = 10−10 m). It is, therefore, not clear whether spin-polarized deuterium should be self-bound or not. For spin-polarized T↓, we obtain theoretical results for the ground-state binding energy per particle from −4.73 K at an equilibrium particle density of 0.41 σ−3 or a molar volume of 74 cm3/mol to −1.21 K at an equilibrium particle density of 0.28 σ−3 or a molar volume of 109 cm3/mol.

A First Principles Examination of Phase Stability in Fcc-Based Ni-V Substitutional Alloys

1990 ◽  
Vol 186 ◽  
Author(s):  
J. Mikalopas ◽  
P.E.A. Turchi ◽  
M. Sluiter ◽  
P.A. Sterne
Keyword(s):  
Phase Stability ◽  
Ground State ◽  
First Principles ◽  
Cluster Variation Method ◽  
Variation Method ◽  
Many Body ◽  
Cluster Variation ◽  
Many Body Interactions ◽  
Ground State Energies ◽  
Substitutional Alloys

AbstractThe phase stability of fcc-based Ni-V substitutional alloys is investigated using linear muffin-tin orbitals total energy (LMTO) calculations. The method of Connolly and Williams (CWM) is used to extract many body interactions from the ground state energies of selected ordered configurations. These interactions are used in conjunction with the cluster variation method (CVM) to calculate the alloy phase diagram. The dependence of the interactions on the choice of configurations used to calculate them is examined.

INVESTIGATION OF NON-MAGNETIC AND FERROMAGNETIC PHASES OF 3D ELECTRON CRYSTAL WITH NaCl AND CsCl STRUCTURES

2008 ◽  
Vol 22 (21) ◽  
pp. 3627-3640
Author(s):  
R. RAJESWARA PALANICHAMY ◽  
M. ANANDAJOTHI ◽  
A. JAWAHAR ◽  
K. IYAKUTTI
Keyword(s):  
Ground State ◽  
State Energy ◽  
Correlation Energy ◽  
Magnetic Phase ◽  
Ferromagnetic Phase ◽  
Density Region ◽  
Wannier Functions ◽  
Ground State Energies ◽  
Electron Crystal

The non-magnetic and ferromagnetic phases of 3D Wigner electron crystal are investigated using a localized representation of the electrons with NaCl and CsCl structures. The ground state energies of ferromagnetic and non-magnetic phases of Wigner electron crystal are computed in the range 10 ≤ rs ≥ 130. The role of correlation energy is suitably taken into account. The low density region favorable for the ferromagnetic phase is found to be 4.8 × 1020 electrons/cm3 and for the non-magnetic phase, it is 2.03 × 1020 electrons/cm3. It is found that the ground state energy of ferromagnetic phase is less than that of the non-magnetic phase of the Wigner electron crystal. The structure-dependent Wannier functions, which give proper localized representation for Wigner electrons, are employed in the calculation.

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

TABLE OF GROUND STATE PROPERTIES OF NUCLEI IN THE RMF MODEL

2013 ◽  
Vol 28 (16) ◽  
pp. 1350068 ◽  
Author(s):  
TUNCAY BAYRAM ◽  
A. HAKAN YILMAZ
Keyword(s):  
Ground State ◽  
Mean Field ◽  
Properties Of Nuclei ◽  
Relativistic Mean Field ◽  
Ground State Properties ◽  
Pairing Correlations ◽  
Ground State Energies ◽  
Rmf Model

The ground state energies, sizes and deformations of 1897 even–even nuclei with 10≤Z ≤110 have been carried out by using the Relativistic Mean Field (RMF) model. In the present calculations, the nonlinear RMF force NL3* recent refitted version of the NL3 force has been used. The BCS (Bardeen–Cooper–Schrieffer) formalism with constant gap approximation has been taken into account for pairing correlations. The predictions of RMF model for the ground state properties of some nuclei have been discussed in detail.

SPIN-POLARIZED ATOMIC DEUTERIUM (↓D) IN THE STATIC FLUCTUATION APPROXIMATION (SFA)

2008 ◽  
Vol 22 (03) ◽  
pp. 257-266 ◽  
Author(s):  
A. S. SANDOUQA ◽  
B. R. JOUDEH ◽  
M. K. AL-SUGHEIR ◽  
H. B. GHASSIB
Keyword(s):  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Ideal Gas ◽  
Hard Sphere Model ◽  
Spin Polarized ◽  
Static Fluctuation Approximation ◽  
Static Fluctuation ◽  
Type Potential ◽  
The Ideal

Spin-polarized atomic deuterium (↓D) is investigated in the static fluctuation approximation with a Morse-type potential. The thermodynamic properties of the system are computed as functions of temperature. In addition, the ground-state energy per atom is calculated for the three species of ↓D : ↓D 1, ↓D 2, and ↓D 3. This is then compared to the corresponding ground-state energy per atom for the ideal gas, and to that obtained by the perturbation theory of the hard sphere model. It is deduced that ↓D is nearly ideal.

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