DOI: 10.17188/1731706
title: Materials Data on Ta18Ti15Se52 by Materials Project

description: Ti13Ta10Se32(TiTaSe4)2(TaSe2)6 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of three TaSe2 sheets oriented in the (0, 0, 1) direction; one Ti13Ta10Se32 sheet oriented in the (0, 0, 1) direction; and two TiTaSe4 sheets oriented in the (0, 0, 1) direction. In each TaSe2 sheet, there are two inequivalent Ta sites. In the first Ta site, Ta is bonded to six Se atoms to form edge-sharing TaSe6 octahedra. There are a spread of Ta–Se bond distances ranging from 2.57–2.67 Å. In the second Ta site, Ta is bonded to six Se atoms to form edge-sharing TaSe6 octahedra. There are a spread of Ta–Se bond distances ranging from 2.57–2.67 Å. There are four inequivalent Se sites. In the first Se site, Se is bonded in a distorted T-shaped geometry to three Ta atoms. In the second Se site, Se is bonded in a distorted T-shaped geometry to three Ta atoms. In the third Se site, Se is bonded in a distorted T-shaped geometry to three Ta atoms. In the fourth Se site, Se is bonded in a distorted T-shaped geometry to three Ta atoms. In the Ti13Ta10Se32 sheet, there are thirteen inequivalent Ti sites. In the first Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with six TiSe6 octahedra, corners with six TaSe6 octahedra, edges with two equivalent TiSe6 octahedra, a faceface with one TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.56–2.67 Å. In the second Ti site, Ti is bonded to six Se atoms to form distorted TiSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, edges with four equivalent TaSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.54–2.80 Å. In the third Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with six TiSe6 octahedra, corners with six TaSe6 octahedra, edges with two equivalent TiSe6 octahedra, a faceface with one TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.56–2.67 Å. In the fourth Ti site, Ti is bonded to six Se atoms to form distorted TiSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, edges with four equivalent TaSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.54–2.80 Å. In the fifth Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with six TaSe6 octahedra, edges with two equivalent TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.55–2.67 Å. In the sixth Ti site, Ti is bonded to six Se atoms to form distorted TiSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, edges with four equivalent TaSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.54–2.81 Å. In the seventh Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with six TiSe6 octahedra, corners with six TaSe6 octahedra, edges with two equivalent TiSe6 octahedra, a faceface with one TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.55–2.66 Å. In the eighth Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with two equivalent TaSe6 octahedra, corners with four equivalent TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.56–2.66 Å. In the ninth Ti site, Ti is bonded to six Se atoms to form distorted TiSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, edges with four equivalent TaSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.54–2.80 Å. In the tenth Ti site, Ti is bonded to six Se atoms to form distorted TiSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, edges with four equivalent TaSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.54–2.80 Å. In the eleventh Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with four equivalent TiSe6 octahedra, edges with two equivalent TiSe6 octahedra, and edges with four equivalent TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 46–51°. There are a spread of Ti–Se bond distances ranging from 2.53–2.75 Å. In the twelfth Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with six TiSe6 octahedra, corners with six TaSe6 octahedra, edges with two equivalent TiSe6 octahedra, a faceface with one TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–Se bond distances ranging from 2.56–2.67 Å. In the thirteenth Ti site, Ti is bonded to six Se atoms to form TiSe6 octahedra that share corners with six TiSe6 octahedra, corners with six TaSe6 octahedra, edges with two equivalent TiSe6 octahedra, a faceface with one TiSe6 octahedra, and a faceface with one TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 46–54°. There are a spread of Ti–Se bond distances ranging from 2.55–2.64 Å. There are ten inequivalent Ta sites. In the first Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with two equivalent TiSe6 octahedra, edges with six TaSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ta–Se bond distances ranging from 2.60–2.70 Å. In the second Ta site, Ta is bonded in a 6-coordinate geometry to six Se atoms. There are a spread of Ta–Se bond distances ranging from 2.58–2.83 Å. In the third Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with four equivalent TiSe6 octahedra and edges with six TaSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ta–Se bond distances ranging from 2.55–2.83 Å. In the fourth Ta site, Ta is bonded in a 6-coordinate geometry to six Se atoms. There are a spread of Ta–Se bond distances ranging from 2.58–2.84 Å. In the fifth Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TaSe6 octahedra, edges with four equivalent TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ta–Se bond distances ranging from 2.57–2.78 Å. In the sixth Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TaSe6 octahedra, edges with four equivalent TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ta–Se bond distances ranging from 2.57–2.78 Å. In the seventh Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TaSe6 octahedra, edges with four equivalent TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ta–Se bond distances ranging from 2.57–2.78 Å. In the eighth Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TaSe6 octahedra, edges with four equivalent TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ta–Se bond distances ranging from 2.57–2.79 Å. In the ninth Ta site, Ta is bonded to six Se atoms to form distorted TaSe6 octahedra that share corners with six TiSe6 octahedra, edges with two equivalent TaSe6 octahedra, edges with four equivalent TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ta–Se bond distances ranging from 2.57–2.76 Å. In the tenth Ta site, Ta is bonded to six Se atoms to form TaSe6 octahedra that share corners with two equivalent TiSe6 octahedra, edges with two equivalent TaSe6 octahedra, edges with four equivalent TiSe6 octahedra, and a faceface with one TiSe6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ta–Se bond distances ranging from 2.57–2.68 Å. There are thirty-one inequivalent Se sites. In the first Se site, Se is bonded in a 4-coordinate geometry to one Ti and three Ta atoms. In the second Se site, Se is bonded in a distorted trigonal non-coplanar geometry to three Ta atoms. In the third Se site, Se is bonded in a 4-coordinate geometry to one Ti and three Ta atoms. In the fourth Se site, Se is bonded in a 5-coordinate geometry to two equivalent Ti and three Ta atoms. In the fifth Se site, Se is bonded in a 4-coordinate geometry to two Ti and two equivalent Ta atoms. In the sixth Se site, Se is bonded in a 5-coordinate geometry to two equivalent Ti and three Ta atoms. In the seventh Se site, Se is bonded in a 5-coordinate geometry to three Ti and two equivalent Ta atoms. In the eighth Se site, Se is bonded in a distorted T-shaped geometry to three Ta atoms. In the ninth Se site, Se is bonded in a 4-coordinate geometry to two Ti and two equivalent Ta atoms. In the tenth Se site, Se is bonded in a 5-coordinate geometry to two equivalent Ti and three Ta atoms. In the eleventh Se site, Se is bonded in a 5-coordinate geometry to three Ti and two equivalent Ta atoms. In the twelfth Se site, Se is bonded in a 4-coordinate geometry to one Ti and three Ta atoms. In the thirteenth Se site, Se is bonded in a 4-coordinate geometry to two Ti and two equivalent Ta atoms. In the fourteenth Se site, Se is bonded in a 5-coordinate geometry to four Ti and one Ta atom. In the fifteenth Se site, Se is bonded in a 5-coordinate geometry to three Ti and two equivalent Ta atoms. In the sixteenth Se site, Se is bonded in a 4-coordinate geometry to three Ti and one Ta atom. In the seventeenth Se site, Se is bonded in a 4-coordinate geometry to two Ti and two equivalent Ta atoms. In the eighteenth Se site, Se is bonded in a 5-coordinate geometry to four Ti and one Ta atom. In the nineteenth Se site, Se is bonded in a 5-coordinate geometry to three Ti and two equivalent Ta atoms. In the twentieth Se site, Se is bonded in a 4-coordinate geometry to three Ti and one Ta atom. In the twenty-first Se site, Se is bonded in a 4-coordinate geometry to two Ti and two equivalent Ta atoms. In the twenty-second Se site, Se is bonded in a 5-coordinate geometry to three Ti and two equivalent Ta atoms. In the twenty-third Se site, Se is bonded in a 4-coordinate geometry to three Ti and one Ta atom. In the twenty-fourth Se site, Se is bonded in a distorted T-shaped geometry to one Ti and two equivalent Ta atoms. In the twenty-fifth Se site, Se