Moments of the probability density function of R₂ approached via conditional probabilities. II. Completely correct and completely incorrect models in space group P

With the help of conditional probabilities formulas are derived for the first and second moment of R₂ as a function of the size of the model. The formulas are valid in the space group P for two extreme cases, viz completely correct and completely incorrect models. Incorporation of the observed intensities enables one to obtain accurate a priori estimates of (R₂) and σ(R₂). The theory agrees very well with simulated experiments.