Figure 6

(a) Calculated interatomic distances evolution of selected compositions as a function of ρ/ρ₀ the filled squares shows the average distances within the first shell consisting of 4 neighbors while the half filled circles show the average distances of the 5th and the 6th neighbors. The dashed red line corresponds to the minimum r_min of the pair correlation function and serves to split the first from the second shell of neighbors. (b) Computed bond angle distributions Ge-Se-Ge with increasing pressure for Ge₂₀Se₈₀ (c) Reduced density dependence of the angle distributions split into neighbor number of the selected compositions obtained from CPMD simulations. Here 0 stands for a central Ge atom in a tetrahedron and the numbers 1, 2, 3, 4, 5 and 6 represent the neighbors (i.e. 102 indicates the angle between the first and 2nd neighbor of the central Ge atom labeled 0. (d) Computed bond angle distributions Se-Ge-Se with increasing pressure for Ge₂₀Se₈₀. The color code in panel b is the same as in panel d.