Materials Data on Na2MgGeO4 by Materials Project
Na2MgGeO4 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with four equivalent NaO4 tetrahedra, corners with four equivalent MgO4 tetrahedra, and corners with four equivalent GeO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.35–2.41 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with four equivalent NaO4 tetrahedra, corners with four equivalent MgO4 tetrahedra, and corners with four equivalent GeO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.29–2.36 Å. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with four equivalent GeO4 tetrahedra and corners with eight NaO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.96–1.99 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four equivalent MgO4 tetrahedra and corners with eight NaO4 tetrahedra. There is two shorter (1.78 Å) and two longer (1.79 Å) Ge–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Na1+, one Mg2+, and one Ge4+ atom to form distorted corner-sharing ONa2MgGe tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Mg2+, and one Ge4+ atom. In the third O2- site, O2- is bonded to two Na1+, one Mg2+, and one Ge4+ atom to form distorted corner-sharing ONa2MgGe trigonal pyramids. In the fourth O2- site, O2- is bonded to two Na1+, one Mg2+, and one Ge4+ atom to form distorted corner-sharing ONa2MgGe tetrahedra.