Scale to an overlap (s1+s2-d)/d < OMMAX1, keeping s1/s2 ratio. s1 and s2 are the two sphere radii and d is the distance between the centers of the spheres. The three numbers are for atom-atom, atom-interstitial, and interstitial-interstitial overlap, respectively. The default values are: 0.16, 0.18, and 0.20.