Table 4. Comparison of the refinements.
The MDO3:MDO4 ratio was derived from the occupancy of the O3/O3′ positions. The (MDO1/2):(MDO3/4) ratio was determined from the occupancy ratio of the Te/Mg positions.
| Family | 1:1 MDO3/4 | MDO3 | MDO4 | |
|---|---|---|---|---|
| Space group | F4/mmm | I41/amd | I41/a | I\overline{4}2d |
| MDO3:MDO4 | 1:1 | 1:1 | 64:35 (3) | 52.8:47.2 (12) |
| MDO1/2:MDO3/4 | 1:1 | 9.2:90.8 (12) | 15.4:84.6 (8) | 13.6:86.4 (6) |
| R[F 2 > 3σ(F 2)], wR(F) | 0.0121, 0.0313 | 0.0204, 0.0782 | 0.0176, 0.0678 | 0.0166, 0.0581 |
| S | 1.33 | 1.61 | 1.34 | 1.17 |
| Δρmin, Δρmax (eÅ−3) | −0.45, 0.27 | −0.90, 1.23 | −0.71, 0.93 | −0.70, 0.80 |
| Coefficient of extinction (Becker & Coppens, 1974 ▸) | 490 (110) | 800 (200) | 960 (170) | 750 (140) |
| No. of parameters | 11 | 24 | 28 | 27 |
| Twin operation | – | – | m [100] | \overline{1} |
| Twin volume fractions | – | – | 50.4:49.6 (6) | 51:49 (9) |