Materials Data on KNaTiH2O3F4 by Materials Project
KNaTiH2O3F4 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one KNaTiH2O3F4 sheet oriented in the (0, 0, 1) direction. K is bonded in a 6-coordinate geometry to three O and three F atoms. There are a spread of K–O bond distances ranging from 2.69–2.77 Å. There are a spread of K–F bond distances ranging from 2.66–2.86 Å. Na is bonded in a 6-coordinate geometry to six F atoms. There are a spread of Na–F bond distances ranging from 2.27–2.73 Å. Ti is bonded to two O and five F atoms to form distorted edge-sharing TiO2F5 pentagonal bipyramids. There is one shorter (1.87 Å) and one longer (1.89 Å) Ti–O bond length. There are a spread of Ti–F bond distances ranging from 1.91–2.20 Å. There are two inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are three inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to one K, one Ti, and one O atom. The O–O bond length is 1.45 Å. In the second O site, O is bonded in a water-like geometry to one K and two H atoms. In the third O site, O is bonded in a 1-coordinate geometry to one K, one Ti, and one O atom. There are four inequivalent F sites. In the first F site, F is bonded in a 2-coordinate geometry to one K, one Na, and one Ti atom. In the second F site, F is bonded to one K, two equivalent Na, and one Ti atom to form distorted corner-sharing FKNa2Ti tetrahedra. In the third F site, F is bonded in a distorted trigonal planar geometry to one K, one Na, and one Ti atom. In the fourth F site, F is bonded in a 4-coordinate geometry to two equivalent Na and two equivalent Ti atoms.