Materials Data on K2Na4Ge2O7 by Materials Project
K2Na4Ge2O7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.71–2.96 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.76–3.35 Å. In the third K1+ site, K1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.77–3.26 Å. In the fourth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.69–3.08 Å. There are eight inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.87 Å. In the second Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.26–2.61 Å. In the third Na1+ site, Na1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.25–2.59 Å. In the fourth Na1+ site, Na1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.87 Å. In the fifth Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share corners with three GeO4 tetrahedra and an edgeedge with one GeO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.30–2.76 Å. In the sixth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.55 Å. In the seventh Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share corners with three GeO4 tetrahedra and an edgeedge with one GeO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.29–2.72 Å. In the eighth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.61 Å. There are four inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one GeO4 tetrahedra and corners with two equivalent NaO5 trigonal bipyramids. There are a spread of Ge–O bond distances ranging from 1.75–1.86 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one GeO4 tetrahedra, a cornercorner with one NaO5 trigonal bipyramid, and an edgeedge with one NaO5 trigonal bipyramid. There are a spread of Ge–O bond distances ranging from 1.77–1.83 Å. In the third Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one GeO4 tetrahedra and corners with two equivalent NaO5 trigonal bipyramids. There are a spread of Ge–O bond distances ranging from 1.76–1.86 Å. In the fourth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one GeO4 tetrahedra, a cornercorner with one NaO5 trigonal bipyramid, and an edgeedge with one NaO5 trigonal bipyramid. There are a spread of Ge–O bond distances ranging from 1.77–1.84 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to three K1+ and two Ge4+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two K1+, two Na1+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 6-coordinate geometry to two K1+, three Na1+, and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to two K1+, three Na1+, and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two Na1+, and one Ge4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, two Na1+, and two Ge4+ atoms. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to two K1+, three Na1+, and one Ge4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, three Na1+, and one Ge4+ atom. In the ninth O2- site, O2- is bonded in a 6-coordinate geometry to one K1+, four Na1+, and one Ge4+ atom. In the tenth O2- site, O2- is bonded in a 5-coordinate geometry to one K1+, three Na1+, and one Ge4+ atom. In the eleventh O2- site, O2- is bonded in a 6-coordinate geometry to two K1+, three Na1+, and one Ge4+ atom. In the twelfth O2- site, O2- is bonded in a 5-coordinate geometry to one K1+, three Na1+, and one Ge4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted octahedral geometry to one K1+, four Na1+, and one Ge4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two K1+, three Na1+, and one Ge4+ atom.