Change in radius of the minority atom on alloying i.e. RA − rA is plotted versus RA/RB for MoSi2-type compounds. rA is the radius of the A atom in the structure and is calculated from the lattice parameters as 0.5[(a2/2) + (c2/36)]1/2. The plot is linear and RA − rA is almost zero when RA/RB = 1. The compounds with = − positive (blue squares) have RA − rA negative, and − increases with the deviation of RA/RB from 1. The compounds with − negative (red open circles) have rA decreasing with increasing RA/RB.