Figure 3: Total radial distribution functions g(r) (left panel) and total structure factors S(q) (right panel) of liquid Ge₂Sb₂Te₅ obtained from AIMD simulations.

Temperatures range from 852 K up to 1250 K. The corresponding partial pair correlation functions g_ij(r) are shown in Fig. 2 (T = 923 K) and in the supplement (T = 852, 1024 and 1250 K). Solid red lines are drawn for the X-ray diffraction structure factors, whereas the S(q) for neutron diffraction are indicated by black lines. In the left panel, vertical dashed lines indicate the position of the first maximum of the vdW-DF2 g(r), underlining the shift to larger particle-particle distances with increasing temperature. GGA AIMD data at T = 926 K are also included. In ref. 27, GGA functionals with van der Waals semi-empirical corrections were employed and a first-peak position of 2.79 Å was obtained for supercooled liquid Ge₂Sb₂Te₅ at T = 820 K.