ESTIMATES OF THE ACCURACY OF CALCULATED CHARGE-DENSITIES

Free atom charge densities are calculated from various atomic Hartree- Fock programs. The differences between the free atom charge density ca lculations from a Hartree-Fock-Slater, Dirac-Slater and Multi-Configur ation Dirac-Fock program are compared with the differences between a p seudopotential solid state charge density and the corresponding free a tom values. Differences between the various Hartree-Fock and Dirac-Foc k calculations can be as high as 3% which is greater than experimental measurement errors for X-ray Pendellosung and electron convergent bea m diffraction.