DOE OSTI2020
Ga4Bi3As is Enargite-like structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Ga sites. In the first Ga site, Ga is bonded to three equivalent Bi and one As atom to form corner-sharing GaBi3As tetrahedra. All Ga–Bi bond lengths are 2.78 Å. The Ga–As bond length is 2.51 Å. In the second Ga site, Ga is bonded to four Bi atoms to form corner-sharing GaBi4 tetrahedra. There are three shorter (2.75 Å) and one longer (2.78 Å) Ga–Bi bond lengths. In the third Ga site, Ga is bonded to four Bi atoms to form corner-sharing GaBi4 tetrahedra. There are three shorter (2.76 Å) and one longer (2.77 Å) Ga–Bi bond lengths. In the fourth Ga site, Ga is bonded to one Bi and three equivalent As atoms to form corner-sharing GaBiAs3 tetrahedra. The Ga–Bi bond length is 2.81 Å. All Ga–As bond lengths are 2.68 Å. There are three inequivalent Bi sites. In the first Bi site, Bi is bonded to four Ga atoms to form BiGa4 tetrahedra that share corners with three equivalent AsGa4 tetrahedra and corners with nine BiGa4 tetrahedra. In the second Bi site, Bi is bonded to four Ga atoms to form corner-sharing BiGa4 tetrahedra. In the third Bi site, Bi is bonded to four Ga atoms to form BiGa4 tetrahedra that share corners with three equivalent AsGa4 tetrahedra and corners with nine BiGa4 tetrahedra. As is bonded to four Ga atoms to form AsGa4 tetrahedra that share corners with six BiGa4 tetrahedra and corners with six equivalent AsGa4 tetrahedra.