1. The problem statement, all variables and given/known data A material contains two types of atoms (A and B) in a zincblende structure. Atom A is group V with a hard sphere radius of 2.5 Å. Atom B is group III with a hard sphere radius of 1.6 Å. (a) What is the lattice constant of this material assuming that nearest neighbour atoms touch? (working on this one right now) (b) What is the volume density of valence electrons in this material? (c) What is the surface density of B atoms on the (110) plane in this material? 2. Relevant equations 3. The attempt at a solution a) Since it's a face centered structure it should have 8X 1/8 + 6* 1/2 atoms, so 4 Is it correct to say ( r1+r2 ) *4 = my lattice constant for A?