Crystal chemistry for \mathrm{CaLn}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9} and \mathrm{CaLn}_{2} \mathrm{ZnTi}_{2} \mathrm{O}_{9}[133](\mathrm{Ln}=\mathrm{La}, \mathrm{Pr}, \mathrm{Nd}, \mathrm{Sm}, \mathrm{Eu}) perovskites with orthorhombic space group P b n m at room temperature.
| t^{a} | t_{0}{ }^{b} | A \mathrm{O}_{8}{ }^{c} | <A-\mathrm{O}>(1)^{d} | <A-\mathrm{O}>(2)^{e} | B \mathrm{O}_{6}{ }^{f} | <B-\mathrm{O}>^{g} | A \mathrm{O}_{12}{ }^{h} | \Psi_{[001]}{ }^{i} | \Phi_{[110]}{ }^{j} | \mathrm{R}_{4}^{+k} | \mathrm{M}_{3}^{+l} | \mathrm{X}_{5}^{+m} | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pr | 0.877 | 0.90(2) | 26.45(1) | 2.54(2) | 3.28(2) | 10.64(1) | 2.00(1) | 50.02(1) | 9.7(2) | 12.8(3) | 1.22(3) | 0.94(3) | 0.53(1) |
| Nd | 0.872 | 0.90(2) | 26.05(1) | 2.52(2) | 3.27(2) | 10.56(1) | 1.99(1) | 49.46(1) | 10.1(2) | 12.9(4) | 1.25(4) | 0.95(4) | 0.55(1) |
| Sm | 0.866 | 0.88(2) | 25.33(1) | 2.49(2) | 3.36(2) | 10.74(1) | 2.01(1) | 49.18(1) | 11.5(2) | 16.0(1) | 1.40(4) | 1.09(4) | 0.70(2) |
| Crystal chemistry of \mathrm{CaLn}_{2} \mathrm{ZnTiO}_{9} [133] | |||||||||||||
| La | 0.883 | 0.921(1) | 26.97(1) | 2.60(1) | 3.15(1) | 10.55(1) | 1.99(1) | 50.66(1) | 8.25(7) | 11.203(1) | 1.052(7) | 0.812(9) | 0.298(1) |
| Pr | 0.875 | 0.885(1) | 25.82(1) | 2.52(1) | 3.33(1) | 10.85(1) | 2.02(1) | 49.79(1) | 8.96(8) | 18.407(1) | 1.518(9) | 0.863(9) | 0.571(3) |
| Nd | 0.871 | 0.892(1) | 25.92(1) | 2.53(1) | 3.29(1) | 10.70(1) | 2.00(1) | 49.82(1) | 9.72(7) | 14.904(1) | 1.336(7) | 0.949(8) | 0.556(3) |
| Eu | 0.861 | 0.879(1) | 25.28(1) | 2.49(1) | 3.35(1) | 10.74(1) | 2.00(1) | 49.01(1) | 10.66(5) | 16.053(1) | 1.473(5) | 1.036(5) | 0.669(2) |