Figure 3
The [VOXO4] layers (X = P and Si) formed by VO5 square pyramids and tetrahedral XO4 groups in (a) Pb2VO(PO4)2, (b) BaZnVO(PO4)2, (c) LiVOSiO4 and (d) Pb(VO)2(PO4)2·4H2O. (In the latter structure, large circles represent Pb atoms, medium circles O atoms and small circles H atoms.) |