Structure of Sb-Te Compounds

The structure factors, S q), and pair correlation functions, g r) of Sb2Tc3 and Sb2Te in the liquid and amorphous phases are shown in Fig. 18.2. If the overall agreement between experiment and simulation is reasonable, it is not as good as in the case of other chalcogenide glasses, such as GeSc2 [22]. It was established [23] that the discrepancy is mostly due to an over coordination of Te atoms in DFT calculations. However, AIMD simulation reproduce all trends observed experimentally. 

The first g r) peaks positions are at slightly larger distances (by 0.1 A) in the AIMD curve than in the experiment, as discussed in [23], otherwise, the overall agreement is reasonable. 

The first peak position, r, first minimum, rmin, and total coordination numbers Nc from both the experiment and the AIMD are indicated in Table 18.1. Coordination numbers were calculated by integration of Anr pg r) from a fixed distance equal to 2.4 A to a cutoff distance equal to for experiment and for calculations. 

Densities [25], positions of the first maximum r, first minimum rmin and coordination number Nc from experimental and calculated pair correlation functions g(r). All distances are given in A 

Because of the interatomic distances overestimate mentioned before, we observe coordination numbers from AIMD that are slightly larger (by 0.4 in average) than the experimental ones. The values for Sb2Tc3 are in line with those of Caravati et al. [24], given that the cutoff distance was smaller in that study. 

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