Fock coordinate function method for separation of spin variables in transition density matrices

The Fock generating function method is employed for the separation of spin variables into two‐particle transition density matrices. Their spatial components introduced by McWeeny are expressed through Schrödinger's coordinate wave functions. Some nontrivial integral relations between these components and the charge and transition spin density matrices are obtained. The interrelation between the mentioned spatial components and the Matsen–Poshusta symmetrized density matrices of an arbitrary spatial function is found.