The value of the statistical exchange parameter a is, in general, 0.7 for all but the lightest atoms where it rises to about 0.78. A compilation of a values for up to Z=41 can be found from Karlheinz Schwarz, Phys. Rev. B 5 Num. 7, 2466 (1972).
The appropriate value of r(r) to use for the spherically averaged potential about a particular atom may be found as in the previous case of the Coulomb potential. Contributions to r(r) from neighboring atoms take the form
and are added together with the density of the atom of interest to find the total density.
The total spherically averaged potential about each atom is then taken to be
Go to top of page
Created: April 9, 1999 ---- Last Updated: April 12, 1999
By Mark D. Pauli