Table 4. Properties of the charge density ρ(r c) (e Å−3) and the Laplacian ∇2ρ(r c) (e Å−5) at the (3, −1) BCPs of grossular.
d 1-bcp and d 2-bcp (Å) denote the distances from the BCP to atoms 1 and 2, respectively. In the case of theoretical refinements (TRi), the left and right values correspond to results from XD2016 and TOPOND14, respectively.
| X—Y interaction | Si—O | Al—O | Ca—OI † | Ca—OII † | |
|---|---|---|---|---|---|
| d 1-bcp | Exp_Amb | 0.694 | 0.833 | 1.194 | 1.273 |
| Exp_1GPa | 0.696 | 0.853 | 1.191 | 1.266 | |
| TR1 | 0.705 / 0.685 | 0.829 / 0.804 | 1.181 / 1.163 | 1.257 / 1.234 | |
| TR2 | 0.704 / 0.685 | 0.827 / 0.803 | 1.180 / 1.162 | 1.254 / 1.231 | |
| TR3 | 0.703 / 0.684 | 0.826 / 0.801 | 1.178 / 1.160 | 1.249 / 1.228 | |
| TR4 | 0.703 / 0.684 | 0.824 / 0.800 | 1.176 / 1.159 | 1.246 / 1.225 | |
| TR5 | 0.698 / 0.679 | 0.815 / 0.792 | 1.165 / 1.149 | 1.220 / 1.203 | |
| Pyrope | 0.692 | 0.798 | 0.969 | 1.039 | |
| d 2-bcp | Exp_Amb | 0.953 | 1.102 | 1.132 | 1.244 |
| Exp_1GPa | 0.957 | 1.089 | 1.143 | 1.231 | |
| TR1 | 0.955 / 0.974 | 1.095 / 1.120 | 1.151 / 1.165 | 1.237 / 1.257 | |
| TR2 | 0.954 / 0.973 | 1.093 / 1.117 | 1.150 / 1.164 | 1.233 / 1.253 | |
| TR3 | 0.953 / 0.971 | 1.090 / 1.114 | 1.148 / 1.162 | 1.228 / 1.247 | |
| TR4 | 0.951 / 0.970 | 1.088 / 1.112 | 1.147 / 1.159 | 1.224 / 1.243 | |
| TR5 | 0.942 / 0.960 | 1.070 / 1.093 | 1.131 / 1.143 | 1.191 / 1.206 | |
| Pyrope | 0.943 | 1.086 | 1.228 | 1.294 | |
| ρ(r c) | Exp_Amb | 1.15 | 0.51 | 0.19 | 0.18 |
| Exp_1GPa | 1.06 | 0.53 | 0.25 | 0.19 | |
| TR1 | 1.07 / 0.90 | 0.40 / 0.41 | 0.29 / 0.28 | 0.16 / 0.18 | |
| TR2 | 1.07 / 0.91 | 0.40 / 0.41 | 0.30 / 0.28 | 0.16 / 0.18 | |
| TR3 | 1.08 / 0.91 | 0.41 / 0.41 | 0.30 / 0.28 | 0.16 / 0.18 | |
| TR4 | 1.09 / 0.92 | 0.42 / 0.42 | 0.30 / 0.28 | 0.17 / 0.18 | |
| TR5 | 1.12 / 0.95 | 0.44 / 0.45 | 0.32 / 0.30 | 0.19 / 0.21 | |
| Pyrope | 0.89 | 0.49 | 0.27 | 0.21 | |
| ∇2ρ(r c) | Exp_Amb | 8.5 | 3.3 | 5.1 | 2.7 |
| Exp_1GPa | 9.2 | 1.0 | 4.4 | 2.8 | |
| TR1 | 6.0 / 17.2 | 5.0 / 8.0 | 4.2 / 5.1 | 3.3 / 3.4 | |
| TR2 | 6.0 / 17.4 | 5.0 / 8.2 | 4.2 / 5.1 | 3.4 / 3.5 | |
| TR3 | 6.0 / 17.6 | 5.0 / 8.3 | 4.2 / 5.2 | 3.4 / 3.6 | |
| TR4 | 6.0 / 17.7 | 5.1 / 8.4 | 4.3 / 5.2 | 3.5 / 3.6 | |
| TR5 | 6.8 / 19.0 | 6.0 / 9.3 | 4.7 / 5.6 | 4.1 / 4.2 | |
| Pyrope | 17.0 | 8.3 | 3.1 | 1.8 | |
†
Destro et al. (2017 ▸) (Mg instead of Ca).
‡
Two non-equivalent Ca—O contacts exist in this structure.