DOE OSTI2020
La2Au3Ga5 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. La is bonded in a 12-coordinate geometry to six Au and ten Ga atoms. There are four shorter (3.35 Å) and two longer (3.48 Å) La–Au bond lengths. There are a spread of La–Ga bond distances ranging from 3.47–3.60 Å. There are two inequivalent Au sites. In the first Au site, Au is bonded in a 3-coordinate geometry to four equivalent La, two equivalent Au, and three Ga atoms. Both Au–Au bond lengths are 2.74 Å. There are one shorter (2.50 Å) and two longer (2.74 Å) Au–Ga bond lengths. In the second Au site, Au is bonded to four equivalent La, four equivalent Au, and four equivalent Ga atoms to form AuLa4Ga4Au4 cuboctahedra that share corners with four equivalent AuLa4Ga4Au4 cuboctahedra, faces with four equivalent AuLa4Ga4Au4 cuboctahedra, and faces with four equivalent GaLa4Au8 tetrahedra. All Au–Ga bond lengths are 3.17 Å. There are four inequivalent Ga sites. In the first Ga site, Ga is bonded in a 12-coordinate geometry to four equivalent La and four equivalent Ga atoms. All Ga–Ga bond lengths are 2.64 Å. In the second Ga site, Ga is bonded in a 12-coordinate geometry to four equivalent La and four equivalent Ga atoms. All Ga–Ga bond lengths are 2.64 Å. In the third Ga site, Ga is bonded in a distorted single-bond geometry to four equivalent La, one Au, and four Ga atoms. In the fourth Ga site, Ga is bonded to four equivalent La and eight Au atoms to form distorted GaLa4Au8 tetrahedra that share corners with four equivalent GaLa4Au8 tetrahedra, faces with four equivalent AuLa4Ga4Au4 cuboctahedra, and faces with four equivalent GaLa4Au8 tetrahedra.