Probability distribution connected with structure amplitudes of two related crystals. VII. The case of an approximately centrosymmetric structure

The probability distribution of the structure factors F_N and F^c_N, where the former refers to the 'true structure' containing N atoms at locations r_Nj and the latter to the assumed model' with N atoms at locations r^c_Nj, is worked out for the situation where the assumed model is exactly centrosymmetric and the true model is approximately centrosymmetric. Other statistical distributions connected with these, such as difference, quotient, reciprocal quotient and the phase-angle difference have also been derived. Also a Booth type of discrepancy index is worked out for such a situation. Theoretical results are verified with a hypothetical model.