Materials Data on TaSe2 by Materials Project

Abstract

TaSe2 is Molybdenite-like structured and crystallizes in the hexagonal P6_3/m space group. The structure is two-dimensional and consists of four TaSe2 sheets oriented in the (0, 0, 1) direction. In two of the TaSe2 sheets, there are five inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to six Se2- atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. All Ta–Se bond lengths are 2.62 Å. In the second Ta4+ site, Ta4+ is bonded to six Se2- atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. There are two shorter (2.61 Å) and four longer (2.62 Å) Ta–Se bond lengths. In the third Ta4+ site, Ta4+ is bonded to six Se2- atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. There are two shorter (2.61 Å) and four longer (2.62 Å) Ta–Se bond lengths. In the fourth Ta4+ site, Ta4+ is bonded to six Se2- atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. There are four shorter (2.61 Å) and two longer (2.63 Å) Ta–Se bond lengths. In the fifth Ta4+ site, Ta4+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing TaSe6 pentagonal pyramids. All Ta–Se bond lengths are 2.62 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the fifth Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent Ta4+ atoms. In two of the TaSe2 sheets, there are three inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to six Se2- atoms to form edge-sharing TaSe6 octahedra. There are a spread of Ta–Se bond distances ranging from 2.56–2.72 Å. In the second Ta4+ site, Ta4+ is bonded to six Se2- atoms to form edge-sharing TaSe6 octahedra. There are a spread of Ta–Se bond distances ranging from 2.48–2.75 Å. In the third Ta4+ site, Ta4+ is bonded to six equivalent Se2- atoms to form edge-sharing TaSe6 octahedra. All Ta–Se bond lengths are 2.66 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted T-shaped geometry to three equivalent Ta4+ atoms. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms. In the fifth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Ta4+ atoms.