New and refined bond valence parameters for Te⁴⁺–F⁻, Te⁴⁺–S²⁻ and Te⁴⁺–Se²⁻ ion pairs

Abstract New and refined bond valence parameters related to ion pairs constituted of the tellurium Te 4+ cation non-oxide X n − anions ( = F, S or Se) are proposed. After a selection specific crystalline structures, optimization R b with cutoff distance is carried out by minimizing root mean square deviation valence. The results 1.728 Å 0.622 5.3 for –F pair 2.444 0.387 4.5 –S 2− pair. These lead lower dispersion calculated valences around formal compared that obtained available in literature. As new set –Se pair, we find 2.578 0.296 3.7 Å.