Solid hydrogen and deuterium. II. Pressure and compressibility calculated by a lowest-order constrained-variation method

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00116867· OSTI ID:5874556

Pettersen, G; Ostgaard, E

The pressure and the compressibility of solid H/sub 2/ and D/sub 2/ are obtained from ground-state energies calculated by means of a modified variational lowest order constrained-variation (LOCV) method. Both fcc and hcp structures are considered, but results are given for the fcc structure only. 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 of 0.65/sigma//sup /minus/3/ to 1.3/sigma//sup /minus/3/, corresponding to a molar volume of 0.65/sigma//sup /minus/3/ to 1.3/sigma//sup /minus/3/, corresponding to a molar volume of 12-24 cm/sup 3/mole, where /sigma/ = 2.958 /angstrom/, and the calculations are done for five different two-body potentials. Theoretical results for the pressure are 340-460 atm for solid H/sub 2/ at a particle density of 0.82/sigma//sup /minus/3/ or a molar volume of 19 cm/sup 3//mole, and 370-490 atm for solid /sup 4/He at a particle density of 0.92/sigma//sup /minus/3/ or a molar volume of 17 cm/sup 3//mole. The corresponding experimental results are 650 and 700 atm, respectively. Theoretical results for the compressibility are 210 /times/ 10/sup /minus/6/ to 260 /times/ 10/sup /minus/6/ atm/sup /minus/1/ for solid H/sub 2/ at a particle density of 0.82/sigma//sup /minus/3/ or a molar volume of 19 cm/sup 3//mole, and 150 /times/ 10/sup /minus/6/ to 180 /times/ 10/sup /minus/6/ atm/sup /minus/1/ for solid D/sub 2/ at a particle density of 0.92/sigma//sup /minus/3/ or a molar volume of 17 cm/sup 3/mole. The corresponding experimental results are 180 /times/ 10/sup /minus/6/ and 140 /times/ 10/sup /minus/6/ atm/sup /minus/1/, respectively. The agreement with experimental results is better for higher densities.

• Research Organization: Universitetet i Trondheim, Dragvoll (Norway)
• OSTI ID: 5874556
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 71:5-6; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

640460* -- Fluid Physics-- Other Quantum Fluids
656002 -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPRESSIBILITY
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
CUBIC LATTICES
DENSITY
DEUTERIUM
ELEMENTS
ENERGY
ENERGY LEVELS
FCC LATTICES
GROUND STATES
HCP LATTICES
HEXAGONAL LATTICES
HIGH PRESSURE
HYDROGEN
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
MANY-BODY PROBLEM
MECHANICAL PROPERTIES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
PHYSICAL PROPERTIES
POTENTIAL ENERGY
QUANTUM CRYSTALS
SOLIDS
STABLE ISOTOPES
TWO-BODY PROBLEM
VARIATIONAL METHODS