where, S: bonding strength Zt. number of valence electron CNT: C.N. of cation ion if s=s S. Then Z=CN)×S=(CN)×(zCN+)
CN :C.N. of cation ion : number of valence electron where, : bonding strength CN + + + + = Z S Z S if S1＝S2＝……＝S, Then Z ＝(CN－)×S＝（CN－）×（Z + /CN+） + − = − = + = = CN 1 CN 1 , i i i Z Si Z S
3. The anion polyhedron prefer to share apex instead of sharing edges or faces Corner-sharing Edge-sharing Face-sharing tetrahedra tetrahedra tetrahedra (a) (b)
3. The anion polyhedron prefer to share apex instead of sharing edges or faces:
33.5 Crystal Structure of Ceramic Materials AB AB, A2B3 ABO3 AB,Oa Ab type N CI 1. NaCl r/r-=0.54 octahedron =>CN+=6 NaCl Z=1=CN(ZCN)=CN×1/6 .CN=6
§3.5 Crystal Structure of Ceramic Materials AB AB2 A2B3 ABO3 AB2O4 ◆Ⅰ. AB type 1. NaCl r + /r－＝0.54 ∴ octahedron ＝> CN+＝6 Z－＝1＝CN－(Z + /CN+ )＝CN－×1/6 ∴ CN－＝6