Table 1. The fitted parameters, including ADPs, for the X-ray PDF data for the temperatures 100, 300 and 500 K, fitted using an average structure model in PDFgui .
The values of α and Pbx,y,z were held fixed for the refinement.
| Parameter | 100 K | 300 K | 500 K |
|---|---|---|---|
| a (Å) | 4.0595 (6) | 4.0606 (7) | 4.0618 (8) |
| α (°) | 89.9 | 89.9 | 90.0 |
| Pbx,y,z | 0 | 0 | 0 |
| Zn/Nbx,y,z | 0.535 (1) | 0.528 (2) | 0.508 (8) |
| Ox | 0.009 (7) | 0.003 (7) | -0.014 (1) |
| Oy,z | 0.580 (5) | 0.577 (6) | 0.563 (1) |
| U Pb | 0.041 (2) | 0.050 (2) | 0.065 (3) |
| U Zn/Nb | 0.006 (1) | 0.009 (1) | 0.013 (1) |
| U O11 | 0.093 (2) | 0.087 (2) | 0.081 (2) |
| U O22 | 0.055 (2) | 0.059 (2) | 0.071 (4) |