Table 1. Summary of the data collection, reduction and refinement statistics of the three title compounds.
| L-Alanine | α-Glycine | Urea | ||||
|---|---|---|---|---|---|---|
| Data collection | ||||||
| Chemical formula | C3H7NO2 | C2H5NO2 | CH4N2O | |||
| Tilt angle/tilt speed (°) | 0.3/0.6 | 0.5/1.0 | 1.0/2.0 | |||
| Detector distance (mm) | 657 | |||||
| Temperature (K) | 81 | |||||
| Accelerating voltage (kV) | 200 | |||||
| Wavelength (Å) | 0.02508 | |||||
| Data reduction | ||||||
| Space group | P212121 | P21/n |
P 21m
|
|||
| Unit cell a, b, c (Å) | 5.89 (7), 5.99 (11), 12.22 (8) | 5.11 (10), 11.81 (10), 5.44 (8) | 5.596 (3), 5.596 (3), 4.716 (17) | |||
| Angles α, β, γ (°) | 90, 90, 90 | 90, 113.1 (13), 90 | 90, 90, 90 | |||
| Volume (Å−3) | 431 (10) | 302 (9) | 147.70 (11) | |||
| Resolution (Å) | 0.56 | 0.56 | 0.56 | |||
| Total reflections | 5996 | 3755 | 1772 | |||
| Unique reflections | 2145 | 1274 | 457 | |||
| Completeness (%) | 82.7 | 71.2 | 89.9 | |||
| Mean I/σ(I) | 7.8 | 7.1 | 10.6 | |||
| Rint (%) | 16.59 | 16.61 | 12.97 | |||
| Rσ (%) | 12.88 | 14.00 | 9.41 | |||
| Kinematical refinement | IAM | TAAM | IAM | TAAM | IAM | TAAM |
| Reflections used [with I > 2σ(I)] | 2145 (1178) | 1274 (777) | 457 (344) | |||
| Constraints/restraints | 0/0 | 0/0 | 0/0 | |||
| Parameters | 83 | 66 | 21 | |||
| R1 [I > 2σ(I)] | 0.1388 | 0.1313 | 0.1596 | 0.1471 | 0.1756 | 0.1628 |
| wR2 [I > 2σ(I)] | 0.3712 | 0.3658 | 0.3578 | 0.3425 | 0.3856 | 0.3709 |
| R1 (all data) | 0.1907 | 0.1844 | 0.2027 | 0.1917 | 0.1917 | 0.1801 |
| wR2 (all data) | 0.4199 | 0.4138 | 0.3931 | 0.3792 | 0.4002 | 0.3866 |
| GooF | 1.19 | 1.13 | 1.15 | 1.11 | 1.39 | 1.33 |
| Residual potential max/min (Å−2) | 0.207/−0.216 | 0.200/−0.212 | 0.366/−0.434 | 0.322/−0.329 | 0.250/−0.333 | 0.239/−0.315 |