Bond lengths ( \AA), and selected angles ( { }^{\circ}) for \mathrm{CaLn}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9}(L n=\mathrm{Pr}, N d, S m) at room temperature calculated from XRPD pattern with Pbnm space group.
| \mathrm{CaPr}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9} | \mathrm{CaNd}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9} | \mathrm{CaSm}_{2} \mathrm{CuTi}_{2} \mathrm{O}_{9} | |
|---|---|---|---|
| \mathrm{Ca} / \operatorname{LnO}_{12} polyhedra | |||
| \mathrm{Ca} / \operatorname{Ln}-\mathrm{O} 1(\times 1)(\AA) | 2.38(2) | 2.37(2) | 2.31(2) |
| \mathrm{Ca} / Ln _{\text {- } \mathrm{O} 2}(\times 2)(\AA) | 2.40(1) | 2.38(1) | 2.36(1) |
| \mathrm{Ca} / \operatorname{Ln}-\mathrm{O} 1(\times 1)(\AA) | 2.48(1) | 2.46(2) | 2.38(2) |
| \mathrm{Ca} / Ln _{\text {- } \mathrm{O} 2}(\times 2)(\AA) | 2.64(1) | 2.63(1) | 2.61(1) |
| \mathrm{Ca} / Ln _{\text {- } \mathrm{O} 2}(\times 2)(\AA) | 2.68(1) | 2.67(1) | 2.64(1) |
| \mathrm{Ca} / \operatorname{Ln}-\mathrm{O} 1(\times 1)(\AA) | 3.15(2) | 3.14(2) | 3.21(2) |
| \mathrm{Ca} / \operatorname{Ln}-\mathrm{O} 1(\times 1)(\AA) | 3.19(1) | 3.20(2) | 3.35(2) |
| \mathrm{Ca} / L n-\mathrm{O} 2(\times 2)(\AA) | 3.36(1) | 3.37(1) | 3.44(1) |
| <\mathrm{Ca} / Ln-O >8 short { }^{a}(\AA) | 2.54(2) | 2.52(2) | 2.49(2) |
| \mathrm{Cu} / \mathrm{TiO}_{6} octahedra | |||
| \mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 1_{\mathrm{ax}}(\times 2)(\AA) | 1.97(1) | 1.97(1) | 1.98(1) |
| \mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 2_{\text {eq }}(\times 2)(\AA) | 1.99(1) | 1.99(1) | 2.01(1) |
| \mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 2^{\prime}{ }_{\text {eq }}(\times 2)(\AA) | 2.04(1) | 2.03(1) | 2.03(1) |
| <\mathrm{Cu} / \mathrm{Ti}-\mathrm{O}>(\AA) | 2.00(1) | 1.99(1) | 2.01(1) |
| \angle \mathrm{O} 1_{\mathrm{ax}}-\mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 2_{\mathrm{eq}}\left({ }^{\circ}\right) | 89.4(3) | 89.2(3) | 90.0(3) |
| \angle \mathrm{O} 1_{\mathrm{ax}}-\mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 2^{\prime}{ }_{\text {eq }}\left({ }^{\circ}\right) | 89.5(2) | 90.4(2) | 93.1(2) |
| \angle \mathrm{O} 2_{\text {eq }}-\mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 2^{\prime}{ }_{\text {eq }}\left({ }^{\circ}\right) | 90.0(2) | 90.0(2) | 90.4(2) |
| \angle \mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 1_{\mathrm{ax}}-\mathrm{Cu} / \mathrm{Ti}\left({ }^{\circ}\right) | 154.5(5) | 154.1(5) | 147.0(5) |
| \angle \mathrm{Cu} / \mathrm{Ti}-\mathrm{O} 2_{\text {eq }}-\mathrm{Cu} / \mathrm{Ti}\left({ }^{\circ}\right) | 153.3(3) | 152.4(3) | 150.1(3) |