DOE OSTI2020
BaHPO4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are five inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to one H1+ and ten O2- atoms. The Ba–H bond length is 2.87 Å. There are a spread of Ba–O bond distances ranging from 2.72–3.09 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.71–3.19 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.83–3.03 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.84–2.96 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to two H1+ and nine O2- atoms. There are one shorter (2.94 Å) and one longer (3.03 Å) Ba–H bond lengths. There are a spread of Ba–O bond distances ranging from 2.74–3.17 Å. There are five inequivalent P5+ sites. In the first P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.53–1.66 Å. In the second P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.54–1.62 Å. In the third P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.53–1.62 Å. In the fourth P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There is three shorter (1.54 Å) and one longer (1.62 Å) P–O bond length. In the fifth P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.53–1.62 Å. There are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.56 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.54 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.52 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a linear geometry to one Ba2+ and two O2- atoms. There is one shorter (1.03 Å) and one longer (1.46 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a distorted single-bond geometry to two Ba2+ and two O2- atoms. There is one shorter (1.00 Å) and one longer (1.66 Å) H–O bond length. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ba2+, one P5+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ba2+, one P5+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ba2+, one P5+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ba2+, one P5+, and one H1+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one P5+, and one H1+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted water-like geometry to one Ba2+, one P5+, and one H1+ atom. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Ba2+, one P5+, and one H1+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, one P5+, and one H1+ atom. In the sixteenth O2- site, O2- is bonded in a linear geometry to two equivalent Ba2+, one P5+, and one H1+ atom. In the seventeenth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one P5+, and one H1+ atom. In the eighteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one P5+ atom.