Table 6. Comparison of bond lengths (Å), polyhedral volumes, various distortion metrics and hydrogen-bond parameters (Å, °) in β-ammonium carbamate.
The β-ammonium carbamate values are from the outputs of CASTEP and a powder X-ray diffraction experiment
| DFT athermal | X-ray 298 K (Kuhn et al., 2007 ▸) | |
|---|---|---|
| C1—O1 | 1.300 | 1.287 (9) |
| C1—O2 | 1.285 | 1.320 (9) |
| C1—N2 | 1.361 | 1.294 (9) |
| N2—H1 | 1.034 | 0.89 (6) |
| N2—H2 | 1.019 | 0.83 (6) |
| N1—H1 | 1.044 | 0.99 (4) |
| N1—H2 | 1.055 | 1.12 (4) |
| N2—H3 | 1.051 | 0.89 (7) |
| N2—H4 | 1.064 | 0.83 (6) |
| NH4 volume | 0.5987 | 0.5883 |
| Distortion index | 0.0057 | 0.0600 |
| Quadratic elongation | 1.001 | 1.0231 |
| Bond-angle variance | 3.4483 | 65.0215 |
| H1⋯O1 | 1.710 | 1.87 (4) |
| H2⋯O2 | 1.804 | 1.77 (4) |
| H3⋯O2 | 2.074 | 3.01 (6) |
| H4⋯O2 | 2.091 | 2.15 (6) |
| N1—H1⋯O1 | 171.31 | 100.5 (6) |
| N1—H2⋯O2 | 165.40 | 157.2 (8) |
| N2—H3⋯O2 | 171.67 | 115.0 (6) |
| N2—H4⋯O2 | 176.67 | 143 (2) |