“…Expansion of the lattice parameter is generally observed in oxides such as CeO 2 [4][5][6], Fe 2 O 3 [7], MgO [8], TiO 2 (rutile) [9], ZrO 2 [10], BaTiO 3 [11], cubic PbTiO 3 [12], and BiFeO 3 [13]. In contrast, contraction in the lattice parameter, is observed in most metals, such as Au [14][15][16], Ag [17][18][19][20], Sn [21], Bi [21,22], Pt [15,23], Si [24], Cu [25], Ni [25], Pd [26,27], ZnS and CdSe [28,29]. Shrinkage of the Cu-Cu distance up to 9% for very small sizes has been reported by Apai,et al in [25].…”