An approach to generalize any kind of collinear functional in density theory noncollinear functionals is proposed. This satisfies the correct limit for functional, guaranteeing that exact after generalization still spins. Besides, it has well-defined and numerically stable derivatives, a desired feature spin-flip time-dependent theory. Furthermore, provides local torque, hinting at its applicat...

Two sets of rigorous upper bounds on the atomic ionization potential are derived from some known inequalities of the classical analysis. The first set of bounds are expressed in terms of radial expectation values of the electron density; they improve previously found bounds of the same kind and converge to the exact ionization potential. The other bounds depend on various atomic density functio...