Multiconfiguration Hartree-Fock method: Direct diagonalization for the construction of a multielectron basis

A method based on the direct diagonalization of basis states in the framework of the multiconfiguration Hartree-Fock procedure has been proposed for constructing the multielectron basis. With the use of the technique of ladder operators of the orbital angular momentum and spin, this method has been generalized to the case of arbitrary electron configurations. It has been shown that such an approach can be easily implemented on a computer and has low requirements for computational resources in the case of d and f-electrons. The calculations of the multielectron basis states have been exemplified for several electron configurations and various sets of quantum numbers.