Abstract
The atomic scale structure of amorphous AsTe 3 is investigated through X-ray diffraction, firstprinciples molecular dynamics (FPMD), and machine learning interatomic potentials (ML-GAP) obtained by exploiting the ab-initio data. We obtain a good agreement between the measured and modelled diffraction patterns. Our FPMD results show that As and Te obey the 8-N rule with an average coordination numbers of 3 and 2, respectively. We find that small fractions of under and over coordinated As and Te atoms occur in the amorphous phase with about 6% (FPMD), and 13% (ML-GAP) of 3-fold Te. As is found at the center of pyramidal structures predominantly linked through Te n chains rather than rings. Despite the low As concentration in AsTe 3 , its local environment feature a very high chemical disorder that manifests through the occurrence of homopolar bonds including at least 57% of As atoms.