Methods to generate reference total and Pauli kinetic potentials

We have derived a method which allows us to compute the full and the Pauli reference kinetic potentials for atoms and molecules in a real-space representation. This is done by applying the optimized effective potential (OEP) method to the Kohn-Sham noninteracting kinetic energy expression. Additionally, we have also derived a simplified OEP variant based on the common energy denominator approximation which has proven to give much more stable and robust results than the original OEP. Moreover, we have also proved that at the solution point our approach is formally equivalent to the commonly used Bartolotti-Acharya formula.