A probabilistic theory of two-phase seminvariants of first rank via the method of representations. III

The estimation of two-phase seminvariants of first rank is carried out for all space groups. Representations theory [Giacovazzo (1977). Acta Cryst. A33, 933- 944] is suitably combined with the joint probability distribution method. Formulae are obtained which exploit the knowledge of the diffraction magnitudes belonging to the first phasing shell of two-phase seminvariants both via the exponential form the characteristic function and via its Gram-Charlier expansion.