research papers
The first sequence of nested neighborhoods of the two-phase structure seminvariant φ12 = φh1k1 -- φh2k2 in the space group P21 is defined, and conditional probability distributions associated with the first four neighborhoods derived. In the favorable case that the variance of a distribution happens to be small, the distribution yields a particularly reliable value for φ12. The most reliable estimates are obtained when φ12 ≃ 0 or π.