Materials Data on Na4Sr2SiP4 by Materials Project
Na4Sr2SiP4 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to one Si4- and five P1- atoms. The Na–Si bond length is 3.19 Å. There are a spread of Na–P bond distances ranging from 3.08–3.22 Å. In the second Na1+ site, Na1+ is bonded to four P1- atoms to form distorted NaP4 tetrahedra that share corners with two equivalent SiNaSrP4 tetrahedra, corners with six NaP4 tetrahedra, corners with two equivalent NaP4 trigonal pyramids, and an edgeedge with one SiNaSrP4 tetrahedra. There are a spread of Na–P bond distances ranging from 2.91–3.09 Å. In the third Na1+ site, Na1+ is bonded to four P1- atoms to form distorted NaP4 trigonal pyramids that share corners with two equivalent SiNaSrP4 tetrahedra, corners with six NaP4 tetrahedra, corners with two equivalent NaP4 trigonal pyramids, and an edgeedge with one SiNaSrP4 tetrahedra. There are a spread of Na–P bond distances ranging from 2.89–3.06 Å. In the fourth Na1+ site, Na1+ is bonded to four P1- atoms to form distorted NaP4 tetrahedra that share corners with two equivalent SiNaSrP4 tetrahedra, corners with four equivalent NaP4 tetrahedra, corners with four equivalent NaP4 trigonal pyramids, and an edgeedge with one SiNaSrP4 tetrahedra. There are a spread of Na–P bond distances ranging from 2.94–3.12 Å. There are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 5-coordinate geometry to five P1- atoms. There are a spread of Sr–P bond distances ranging from 3.06–3.20 Å. In the second Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to one Si4- and six P1- atoms. The Sr–Si bond length is 3.26 Å. There are a spread of Sr–P bond distances ranging from 3.05–3.40 Å. Si4- is bonded to one Na1+, one Sr2+, and four P1- atoms to form distorted SiNaSrP4 tetrahedra that share corners with four NaP4 tetrahedra, corners with two equivalent NaP4 trigonal pyramids, edges with two NaP4 tetrahedra, and an edgeedge with one NaP4 trigonal pyramid. There are a spread of Si–P bond distances ranging from 2.29–2.35 Å. There are four inequivalent P1- sites. In the first P1- site, P1- is bonded in a 8-coordinate geometry to five Na1+, two equivalent Sr2+, and one Si4- atom. In the second P1- site, P1- is bonded in a 1-coordinate geometry to four Na1+, three Sr2+, and one Si4- atom. In the third P1- site, P1- is bonded in a 8-coordinate geometry to four Na1+, three Sr2+, and one Si4- atom. In the fourth P1- site, P1- is bonded in a 8-coordinate geometry to four Na1+, three Sr2+, and one Si4- atom.