EFFECT OF INACCESSIBLE VOLUME ON INTENSITY STATISTICS - ATOMS IN FIXED SPECIAL POSITIONS

The effect of heavy atoms at fixed special positions on the cumulative distribution function N(z) of the normalised intensity z has been stu died under the assumption that the heavy atoms are surrounded by inacc essible volumes which are excluded by light atoms in the unit cell. In an earlier work, the expected value of the random variable - the mean value of the structure factor of the light atoms was assumed to be ze ro. This restriction has now been removed. It is observed that this ha s a significant effect on the cumulative distribution function of norm alised intensity.