The joint probability distribution function of structure factors with rational indices. V. The estimates

The probabilistic formulae [Giacovazzo, Siliqi & Fernandez-Castano (1999). Acta Cryst. A55, 512-524] relating standard and half-integral index reflect ions are modified for practical applications. The experimental tests prove the reliability of the probabilistic relationships. The approach is further developed to explore whether the moduli of the half-integral index reflect ions can be evaluated in the absence of phase information; i.e. by exploiti ng the moduli of the standard reflections only. The final formulae indicate that estimates can be obtained, even though the reliability factor is a co nstant.