MoAlP2O9 crystallizes in the tetragonal P4/ncc space group. Mo(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(3) atoms. Al(1) is bonded to four equivalent O(1) atoms to form AlO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. P(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Mo(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Mo(1) and one P(1) atom.
MoAlP2O9 crystallizes in the tetragonal P4/ncc space group. Mo(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(3) atoms. The Mo(1)-O(2) bond length is 1.71 Å. All Mo(1)-O(3) bond lengths are 2.02 Å. Al(1) is bonded to four equivalent O(1) atoms to form AlO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. All Al(1)-O(1) bond lengths are 1.75 Å. P(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form PO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra. Both P(1)-O(1) bond lengths are 1.53 Å. Both P(1)-O(3) bond lengths are 1.55 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Mo(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Mo(1) and one P(1) atom.