1. The problem statement, all variables and given/known data At about 1180K iron transforms into fcc structure from bcc structure which is also the structural form at room temperature.Assuming no change in density find the ratio of nearest neighbour distance in fcc structure to that in bcc structure. 2. Relevant equations For fcc nearest neighbour distance is a/ 2(1/2) For bcc " """"""" """" a(31/2) / 2 3. The attempt at a solution I took the ratio of the above formula.I am getting 0.8 .But the given answer is 1.029.Clearly my method is wrong .Please help.