Application of generalized fractional-parentage coefficients in relativistic calculations for atoms and ions

The technique of calculation of angular coefficients in relativistic calculations of complex atom systems is considered. Specific expressions for calculation of angular coefficients, submatrix elements of spheric tensor operators of arbitrary rank as well as for matrix elements of the electrostatic interaction operator are given. Angular terms of matrix elements are expressed through the simple sums of generalized fractional-parentage coefficient products through the submatrix elements of unique tensor operators