Ca3GeO crystallizes in the orthorhombic Imma space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted linear geometry to four equivalent Ge(1) and two equivalent O(1) atoms. In the second Ca site, Ca(2) is bonded in a distorted linear geometry to four equivalent Ge(1) and two equivalent O(1) atoms. Ge(1) is bonded in a 12-coordinate geometry to four equivalent Ca(2) and eight equivalent Ca(1) atoms. O(1) is bonded to two equivalent Ca(2) and four equivalent Ca(1) atoms to form corner-sharing OCa6 octahedra. The corner-sharing octahedral tilt angles range from 10-14°.
Ca3GeO crystallizes in the orthorhombic Imma space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted linear geometry to four equivalent Ge(1) and two equivalent O(1) atoms. There are two shorter (3.19 Å) and two longer (3.49 Å) Ca(1)-Ge(1) bond lengths. Both Ca(1)-O(1) bond lengths are 2.37 Å. In the second Ca site, Ca(2) is bonded in a distorted linear geometry to four equivalent Ge(1) and two equivalent O(1) atoms. There are a spread of Ca(2)-Ge(1) bond distances ranging from 3.07-3.62 Å. Both Ca(2)-O(1) bond lengths are 2.37 Å. Ge(1) is bonded in a 12-coordinate geometry to four equivalent Ca(2) and eight equivalent Ca(1) atoms. O(1) is bonded to two equivalent Ca(2) and four equivalent Ca(1) atoms to form corner-sharing OCa6 octahedra. The corner-sharing octahedral tilt angles range from 10-14°.