DOE OSTI2020
KH2PO4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 2-coordinate geometry to one H1+ and nine O2- atoms. The K–H bond length is 2.93 Å. There are a spread of K–O bond distances ranging from 2.70–3.34 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.76–3.06 Å. There are two 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 1.51–1.59 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 1.51–1.61 Å. There are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.55 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a linear geometry to one K1+ and two O2- atoms. There is one shorter (1.05 Å) and one longer (1.46 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 (1.05 Å) and one longer (1.47 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a linear geometry to two equivalent O2- atoms. Both H–O bond lengths are 1.21 Å. In the fifth H1+ site, H1+ is bonded in a linear geometry to two equivalent O2- atoms. Both H–O bond lengths are 1.21 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one P5+, and one H1+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one P5+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one P5+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one P5+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to one K1+, one P5+, and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one P5+, and one H1+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+, one P5+, and one H1+ atom.