Li2Co2P2O9 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a trigonal non-coplanar geometry to one O(1) and two equivalent O(3) atoms. Co(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Co(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Li(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent Co(1) atoms. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Co(1) and one P(1) atom.
Li2Co2P2O9 crystallizes in the triclinic P-1 space group. Li(1) is bonded in a trigonal non-coplanar geometry to one O(1) and two equivalent O(3) atoms. The Li(1)-O(1) bond length is 1.96 Å. There is one shorter (1.94 Å) and one longer (2.00 Å) Li(1)-O(3) bond length. Co(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form CoO4 tetrahedra that share  a cornercorner with one Co(1)O4 tetrahedra and corners with three equivalent P(1)O4 tetrahedra. The Co(1)-O(1) bond length is 1.95 Å. The Co(1)-O(2) bond length is 1.90 Å. The Co(1)-O(4) bond length is 1.77 Å. The Co(1)-O(5) bond length is 1.85 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form PO4 tetrahedra that share corners with three equivalent Co(1)O4 tetrahedra. The P(1)-O(1) bond length is 1.58 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(5) bond length is 1.56 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Co(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Li(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent Co(1) atoms. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Co(1) and one P(1) atom.