Table 1. Structure of cristobalite X-I at 14.1 GPa.
| Atom | Site | Occupancy | x | y | z | U [Å2] |
|---|---|---|---|---|---|---|
| Si1 | 2d | 1 | 0.5 | 0 | 0 | 0.0420(11) |
| Si2 | 4e | 1 | 0.8601(2) | 0.49817(16) | 0.1207(3) | 0.0314(11) |
| Si3 | 4e | 0.5 | 0.7719(6) | 0.9939(4) | 0.7659(8) | 0.0405(12) |
| O1 | 4e | 1 | 0.7904(4) | 0.2357(6) | 0.5459(6) | 0.0314(11) |
| O2 | 4e | 1 | 0.9555(5) | 0.7244(9) | 0.7098(6) | 0.0389(12) |
| O3 | 4e | 1 | 0.8313(5) | 0.7314(8) | 0.3311(6) | 0.0369(11) |
| O4 | 4e | 1 | 0.9226(5) | 0.2733(8) | 0.9162(6) | 0.0391(11) |
The CCDC number assigned to this structure is 1491299.
Atomic parameters of the structure determined by single-crystal X-ray diffraction. Total number of unique reflexions 207, Rint=4.6%, R1=9.3%, wR2=0.2564, GooF=1.127, 28 parameters refined, 0 restrictions. Lattice parameters: a=6.5700(23) Å, b=4.0633(6) Å, c=6.8345(45) Å, β=98.001(56)°, V=180.69(15) Å3. Composition SiO2, Z=8, ρ=4.416 g cm–3. Space group P21/n (Number 14, b-unique, setting 1). U is displacement paramter. Tranformation matrix to P21/c: [100 0–10 −10–1].