Scaling lengths of elemental metals
Abstract
The average interstitial electron densities n of the elemental alkali, noble, and transition metals were computed as a function of the lattice spacing using a scalar-relativistic total-energy band-structure code. The calculations showed that the average interstitial electron density varied exponentially as exp(-a/LD), where a measures the lattice spacing in terms of the equivalent Wigner-Seitz radius. In principle, the value of LD could be considered to be a new characteristic length for the metals-a density length scale. However, we found that LD is very nearly proportional to the energy length scale LE that enters into the definition of the universal bonding energy relations, i.e., LE~0.85LD. Two consequences of this approximate equality are described. First, the normalized cohesive energy can be usefully approximated by a universal function of the normalized interstitial density. Second, the bulk moduli of the elemental metals can be approximately determined from the Wigner-Seitz radius, the bonding valence, and the density length scale.
- Publication:
-
Physical Review B
- Pub Date:
- November 1998
- DOI:
- 10.1103/PhysRevB.58.13438
- Bibcode:
- 1998PhRvB..5813438S
- Keywords:
-
- 71.15.Nc;
- Total energy and cohesive energy calculations