Na2CaSi crystallizes in the cubic F-43m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a body-centered cubic geometry to four equivalent Na(2) and four equivalent Ca(1) atoms. In the second Na site, Na(2) is bonded to four equivalent Na(1) and four equivalent Si(1) atoms to form distorted edge-sharing NaNa4Si4 tetrahedra. Ca(1) is bonded in a distorted body-centered cubic geometry to four equivalent Na(1) and four equivalent Si(1) atoms. Si(1) is bonded in a body-centered cubic geometry to four equivalent Na(2) and four equivalent Ca(1) atoms.
Na2CaSi crystallizes in the cubic F-43m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a body-centered cubic geometry to four equivalent Na(2) and four equivalent Ca(1) atoms. All Na(1)-Na(2) bond lengths are 3.18 Å. All Na(1)-Ca(1) bond lengths are 3.18 Å. In the second Na site, Na(2) is bonded to four equivalent Na(1) and four equivalent Si(1) atoms to form distorted edge-sharing NaNa4Si4 tetrahedra. All Na(2)-Si(1) bond lengths are 3.18 Å. Ca(1) is bonded in a distorted body-centered cubic geometry to four equivalent Na(1) and four equivalent Si(1) atoms. All Ca(1)-Si(1) bond lengths are 3.18 Å. Si(1) is bonded in a body-centered cubic geometry to four equivalent Na(2) and four equivalent Ca(1) atoms.