Young operators and the Waller–Hartree spinfree method
T. K. Lim · International Journal of Quantum Chemistry · 1975
Abstract The basic equivalent transformation Pσ = (−1)p (Pr)−1 as developed recently [6] is used to transform between the Young operators for a two‐row standard tableau and its conjugate two‐column standard tableau. These Young operators are shown to be the Löwdin spin projectors in the spin function‐dependent methods and the spin projectors in the spin function‐free methods. The sandwich operator of Gallup and the last diagonal element of the matric basis of Matsen are shown to be the special cases of our more general matric projectors. Several different forms of the Löwdin spin projectors, spin projectors, and matric projectors are shown and their relations are discussed.