Table 1. Pressure dependence of the force constant
values of iron bonds in basaltic glass and Fe-rich alloys.
| Sample | Pressure range (GPa) | a (N m−1 GPa−1) | b (N m−1) | R2 |
|---|---|---|---|---|
| Basaltic glass | 0–26 | 1.29 (±0.24) | 184.1 (±4.5) | 0.929 |
| 35–65 | 1.81 (±0.09) | 235.8 (±5.1) | 0.994 | |
| Fe | 0–206 | 1.68 (±0.04) | 211.7 (±4.7) | 0.998 |
| Fe86.8Ni8.6Si4.6 | 0–133 | 2.03 (±0.09) | 174.2 (±6.5) | 0.986 |
| Fe92Ni8* | 8–106 | 2.50 (±0.26) | 167.0 (±17.3) | 0.950 |
| Fe85Si15* | 0–70 | 2.46 (±0.19) | 178.9 (±7.8) | 0.960 |
| Fe3S* | 0–57 | 2.99 (±0.21) | 148.0 (±6.9) | 0.966 |
The linear relationships between the force constant 
and pressure (P) for those samples were expressed as 
, with 
in the unit of N/m and P in the unit of GPa.
*The 
values of iron bonds in Fe92Ni8, Fe85Si15, and Fe3S were calculated from this study and NRIXS data from Lin et al.34,35. The <F> values for Fe85Si15 and Fe3S (corresponding to solid symbols in Fig. 1c,d) at ∼24 GPa from this study are in agreement with those (corresponding to half-filled symbols in Fig. 1c,d) calculated by using the SciPhon software with previous NRIXS data, demonstrating the reproducibility of NRIXS results.