On the application of the Kohn–Sham theory to the calculation of potential energy curves

The application of single-determinant Kohn–Sham theory to the calculation of potential energy curves has been analyzed on the basis of the calculations for three diatomic molecules. Both the non-polarized and the polarized results show that the one-determinant approach does not provide exact potential energy curves for the ground state. These deficiencies cannot be corrected by the correlation potential without explicitly including a dependence on more Slater determinants.