Magnetic resonance study of arsenic bonding sites in ternary chalcogenide glasses

► NQR and high-field NMR study of local structure in ternary chalcogenide glasses. ►75As NQR frequencies and asymmetry parameters of EFG at arsenic sites are obtained. ► Arsenic atoms form nearly symmetric pyramidal structural units in Se-excess glasses. ► Arsenic bondings evolve to highly distorted configurations in Se-deficient glasses. ► Arsenic atoms in Se-deficient glasses form complex structural units with As-As bonds.