Ba2PO4I crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent I(1) atoms. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), two equivalent O(3), and three equivalent I(1) atoms. P(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. I(1) is bonded to two equivalent Ba(1) and three equivalent Ba(2) atoms to form a mixture of distorted corner and edge-sharing IBa5 square pyramids.
Ba2PO4I crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), two equivalent O(4), and two equivalent I(1) atoms. The Ba(1)-O(3) bond length is 2.91 Å. There is one shorter (2.74 Å) and one longer (2.88 Å) Ba(1)-O(1) bond length. There is one shorter (2.77 Å) and one longer (2.91 Å) Ba(1)-O(2) bond length. Both Ba(1)-O(4) bond lengths are 2.75 Å. There is one shorter (3.73 Å) and one longer (3.99 Å) Ba(1)-I(1) bond length. In the second Ba site, Ba(2) is bonded in a 8-coordinate geometry to one O(1), one O(2), one O(4), two equivalent O(3), and three equivalent I(1) atoms. The Ba(2)-O(1) bond length is 2.67 Å. The Ba(2)-O(2) bond length is 2.88 Å. The Ba(2)-O(4) bond length is 2.68 Å. There is one shorter (2.65 Å) and one longer (2.83 Å) Ba(2)-O(3) bond length. There are a spread of Ba(2)-I(1) bond distances ranging from 3.64-3.69 Å. P(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.55 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. I(1) is bonded to two equivalent Ba(1) and three equivalent Ba(2) atoms to form a mixture of distorted corner and edge-sharing IBa5 square pyramids.