DOE OSTI2020
K3TiCl6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to five Cl1- atoms to form distorted KCl5 square pyramids that share corners with three equivalent TiCl6 octahedra, corners with two equivalent KCl6 pentagonal pyramids, and an edgeedge with one KCl6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 25–38°. There are a spread of K–Cl bond distances ranging from 2.92–3.57 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight Cl1- atoms. There are a spread of K–Cl bond distances ranging from 3.11–3.80 Å. In the third K1+ site, K1+ is bonded to six Cl1- atoms to form distorted KCl6 pentagonal pyramids that share a cornercorner with one TiCl6 octahedra, corners with four equivalent KCl6 pentagonal pyramids, corners with two equivalent KCl5 square pyramids, and an edgeedge with one KCl5 square pyramid. The corner-sharing octahedral tilt angles are 58°. There are a spread of K–Cl bond distances ranging from 3.14–3.52 Å. There are two inequivalent Ti3+ sites. In the first Ti3+ site, Ti3+ is bonded in a square co-planar geometry to four Cl1- atoms. There are two shorter (2.31 Å) and two longer (2.36 Å) Ti–Cl bond lengths. In the second Ti3+ site, Ti3+ is bonded to six Cl1- atoms to form TiCl6 octahedra that share corners with two equivalent KCl6 pentagonal pyramids and corners with six equivalent KCl5 square pyramids. There are a spread of Ti–Cl bond distances ranging from 2.36–2.50 Å. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 4-coordinate geometry to three K1+ and one Ti3+ atom. In the second Cl1- site, Cl1- is bonded in a 4-coordinate geometry to four K1+ atoms. In the third Cl1- site, Cl1- is bonded in a 5-coordinate geometry to four K1+ and one Ti3+ atom. In the fourth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to three K1+ and one Ti3+ atom. In the fifth Cl1- site, Cl1- is bonded to three K1+ and one Ti3+ atom to form a mixture of distorted corner and edge-sharing ClK3Ti tetrahedra. In the sixth Cl1- site, Cl1- is bonded in a 3-coordinate geometry to two equivalent K1+ and one Ti3+ atom.