Theoretical aspects of the 5 f delocalization of americium under pressure

Journal Article · Sat Feb 15 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.45.3198· OSTI ID:5004736

Eriksson, O; Wills, J M ^[1]

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1. Center for Materials Science and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Americium is the first element of the actinide series with localized and chemically inert 5{ital f} electrons. It has earlier been demonstrated that with applied pressure the 5{ital f} electrons in Am become itinerant, and therefore bonding. The crystal structure of americium has been experimentally determined to change with increasing pressure; it changes from double hcp{r arrow}fcc{r arrow}monoclinic or distorted fcc{r arrow}the {alpha}-uranium structure (orthorhombic), or a related structure. The experimentally observed volume collapse associated with 5{ital f} delocalization is very small. In contrast, previous theoretical calculations have predicted a volume collapse between 25% and 40%. We present the total energy versus volume of americium in the fcc and in the experimentally reported {alpha}-uranium structure obtained from fully relativistic, full-potential, linear-muffin-tin-orbital calculations based on the local-density approximation. In combination with previous calculations for the low-pressure phase, our calculations predict that 2 the delocalization of the 5f electrons in americium is accompanied by a {similar to}34% volume collapse.

• OSTI ID: 5004736
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 45:7; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
665000 -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDES
AMERICIUM
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
CUBIC LATTICES
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY
ENERGY LEVELS
F STATES
FCC LATTICES
HCP LATTICES
HEXAGONAL LATTICES
LCAO METHOD
METALS
MUFFIN-TIN POTENTIAL
ORTHORHOMBIC LATTICES
PHASE TRANSFORMATIONS
POTENTIALS
PRESSURE DEPENDENCE
TRANSPLUTONIUM ELEMENTS
TRANSURANIUM ELEMENTS