Analysis of a possible of X-ray approach to a study fine rides crystallographic properties for Ca, REM and Th hexabo

The effect of boron atom position inside the CaB6 unit cell on the X-ray reflex intensity I is studied theoretically. The intensity varies periodically with B atoms displacement from the centre to the cubic cell face. Despite highly expressed I variations accompanying the B atom displacement at a considerable distance, I changes very slightly with a 0.01-0.05 A atom displacement from equidistant position towards the cell faces. Experimental accuracy of the I measurement is estimated which is necessary for precision determination of B atom coordinates in CaB6, LaB6, YbB6 and ThB6. To make the determination of an actual position of B atoms in the MeB6 structures more precise with X-ray analysis it is necessary to measure intensity with a very high accuracy (2%). In this case measurement accuracy of the B atom x coordinate decreases with an increase in the atomic number of a hexaboride-forming metal