Example 1.(FCC) b=AB=-[101 2[101→>[211+121 B 2 ∑ 262=V6 [12] a X 2 cO C ∑b2>∑b2◆ Ⅱ.Example 1. (FCC) [ 110 ] [ 211 ] [ 1 2 1 ] 61 61 21 → + 2 2 2 2 2 2 2 2 2 31 ) 2 66 ( 21 42 ) 22 (     =  = = = = i j j j i i b b b a a b a a a    [ 110 ] 21 b = AB =  B B C [11 2 ]