Materials Data on TbSi4B18C by Materials Project

Abstract

TbB18Si4C crystallizes in the monoclinic C2/m space group. The structure is three-dimensional and consists of four terbium molecules and one B18Si4C framework. In the B18Si4C framework, there are ten inequivalent B sites. In the first B site, B is bonded in a 1-coordinate geometry to five B and one Si atom. There are a spread of B–B bond distances ranging from 1.76–1.81 Å. The B–Si bond length is 1.99 Å. In the second B site, B is bonded in a 6-coordinate geometry to five B and one Si atom. There are a spread of B–B bond distances ranging from 1.77–1.80 Å. The B–Si bond length is 2.02 Å. In the third B site, B is bonded in a 6-coordinate geometry to five B and one Si atom. There are a spread of B–B bond distances ranging from 1.79–1.83 Å. The B–Si bond length is 2.07 Å. In the fourth B site, B is bonded in a 6-coordinate geometry to six B atoms. There are a spread of B–B bond distances ranging from 1.71–1.86 Å. In the fifth B site, B is bonded in a 6-coordinate geometry to six B atoms. There are a spread of B–B bond distances ranging from 1.74–1.84 Å. In the sixth B site, B is bonded in a 6-coordinate geometry to six B atoms. There is one shorter (1.79 Å) and one longer (1.82 Å) B–B bond length. In the seventh B site, B is bonded in a distorted single-bond geometry to five B and one C4- atom. The B–B bond length is 1.85 Å. The B–C bond length is 1.69 Å. In the eighth B site, B is bonded in a single-bond geometry to five B and one C4- atom. The B–B bond length is 1.85 Å. The B–C bond length is 1.67 Å. In the ninth B site, B is bonded in a 6-coordinate geometry to five B and one Si atom. The B–Si bond length is 2.02 Å. In the tenth B site, B is bonded in a 6-coordinate geometry to five B and one Si atom. The B–Si bond length is 2.08 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four Si atoms to form corner-sharing SiSi4 tetrahedra. There are a spread of Si–Si bond distances ranging from 2.33–2.36 Å. In the second Si site, Si is bonded to three B and one Si atom to form distorted corner-sharing SiSiB3 tetrahedra. In the third Si site, Si is bonded in a distorted trigonal non-coplanar geometry to three B and one Si atom. C4- is bonded in a distorted tetrahedral geometry to three B and one C4- atom. The C–C bond length is 1.66 Å.