Theoretical Calculation of Ground term for the Cr Atom
As we pointed out earlier there are some discrepancies from the expected
filling of the Madelung prediction for half-filled and full filled d and
f shells. Here we mainly concentrate on the Cr atom where the expected
filling is 4s23d4 but the true
occupation is 4s13d5. Here we mainly
tried to find out the energy differences of these two different
configurations by self consistently. It is obvious that the term symbol
for 4s23d4 and
4s13d5 would be 5D
and 7S respectively.
Many authors have calculated the Hartree-Fock energy of these two
different configuration in order to work out the deviation from the
Madelung rule. Hartree-Fock is the usual method for exploiting the
exceptions of the Madelung rule. Apart from the literature, we have used
the Gaussian Software to compute the total energies of the electronic
configurations of the Cr atom. In table 1 we have compared those works
in the literature with our results.