Materials Data on CaEuSi4 by Materials Project

Abstract

CaEuSi4 is hexagonal omega structure-derived structured and crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. Ca is bonded to twelve Si atoms to form CaSi12 cuboctahedra that share edges with four equivalent CaSi12 cuboctahedra, edges with eight equivalent EuSi12 cuboctahedra, faces with four equivalent CaSi12 cuboctahedra, and faces with four equivalent EuSi12 cuboctahedra. There are four shorter (3.10 Å) and eight longer (3.23 Å) Ca–Si bond lengths. Eu is bonded to twelve Si atoms to form EuSi12 cuboctahedra that share edges with four equivalent EuSi12 cuboctahedra, edges with eight equivalent CaSi12 cuboctahedra, faces with four equivalent CaSi12 cuboctahedra, and faces with four equivalent EuSi12 cuboctahedra. There are four shorter (3.10 Å) and eight longer (3.23 Å) Eu–Si bond lengths. There are five inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ca, two equivalent Eu, and three Si atoms. There are one shorter (2.30 Å) and two longer (2.40 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to two equivalent Ca, four equivalent Eu, and three Si atoms. The Si–Si bond length is 2.29 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to two equivalent Ca, four equivalent Eu, and three Si atoms. There are one shorter (2.29 Å) and two longer (2.40 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ca, two equivalent Eu, and three Si atoms. All Si–Ca bond lengths are 3.23 Å. Both Si–Eu bond lengths are 3.10 Å. There are one shorter (2.30 Å) and two longer (2.40 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ca, two equivalent Eu, and three Si atoms. All Si–Ca bond lengths are 3.23 Å. Both Si–Si bond lengths are 2.40 Å.