Matrix elements of the Breit-Pauli hamiltonian and singlet-triplet mixing in the helium iso-electronic sequence Back to all publications Publication date 1 January 1972 Reference R.K. van den Eynde, G. Wiebes and Th. Niemeyer, Matrix elements of the Breit-Pauli hamiltonian and singlet-triplet mixing in the helium iso-electronic sequence, Physica 59, 401-418 (1972)
