Materials Data on K2Na3SiP3 by Materials Project
K2Na3SiP3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to two equivalent Si4- and five P+0.33- atoms. Both K–Si bond lengths are 3.36 Å. There are a spread of K–P bond distances ranging from 3.24–3.33 Å. In the second K1+ site, K1+ is bonded in a 5-coordinate geometry to five P+0.33- atoms. There are a spread of K–P bond distances ranging from 3.38–3.75 Å. There are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 1-coordinate geometry to two equivalent Si4- and five P+0.33- atoms. Both Na–Si bond lengths are 3.20 Å. There are a spread of Na–P bond distances ranging from 2.93–3.25 Å. In the second Na1+ site, Na1+ is bonded to four P+0.33- atoms to form corner-sharing NaP4 tetrahedra. There are a spread of Na–P bond distances ranging from 2.93–2.97 Å. In the third Na1+ site, Na1+ is bonded in a 1-coordinate geometry to two equivalent Si4- and five P+0.33- atoms. Both Na–Si bond lengths are 3.21 Å. There are a spread of Na–P bond distances ranging from 3.03–3.26 Å. Si4- is bonded in a distorted trigonal planar geometry to two equivalent K1+, four Na1+, and three P+0.33- atoms. There are one shorter (2.18 Å) and two longer (2.20 Å) Si–P bond lengths. There are three inequivalent P+0.33- sites. In the first P+0.33- site, P+0.33- is bonded in a 9-coordinate geometry to three K1+, five Na1+, and one Si4- atom. In the second P+0.33- site, P+0.33- is bonded in a 2-coordinate geometry to five K1+, three Na1+, and one Si4- atom. In the third P+0.33- site, P+0.33- is bonded in a 9-coordinate geometry to two equivalent K1+, six Na1+, and one Si4- atom.