DOI: 10.17188/1285140
title: Materials Data on KMg2As2H31O23 by Materials Project

description: (K2Mg3As2(H11O12)2)2(MgAs2H23O18)2(H2)9(H2O)8 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of five hydrogen molecules; four water molecules; one MgAs2H23O18 ribbon oriented in the (-1, 1, 0) direction; and one K2Mg3As2(H11O12)2 sheet oriented in the (0, 0, 1) direction. In the MgAs2H23O18 ribbon, Mg2+ is bonded in an octahedral geometry to six O2- atoms. There are four shorter (2.00 Å) and two longer (2.30 Å) Mg–O bond lengths. As5+ is bonded in a 2-coordinate geometry to one H1+ and three O2- atoms. The As–H bond length is 1.77 Å. There are a spread of As–O bond distances ranging from 1.74–2.46 Å. There are twelve inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two equivalent As5+ atoms. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.06 Å) and one longer (1.43 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 (1.04 Å) and one longer (1.51 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fifth H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.70 Å) H–O bond length. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eleventh H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.59 Å) H–O bond length. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Mg2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one H1+ and one O2- atom. The O–O bond length is 1.47 Å. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, two H1+, and one O2- atom. The O–O bond length is 1.51 Å. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one As5+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one As5+ and one O2- atom. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to three H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Mg2+, one H1+, and one O2- atom. In the eighth O2- site, O2- is bonded in a water-like geometry to one As5+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to three H1+ atoms. In the K2Mg3As2(H11O12)2 sheet, K1+ is bonded in a 5-coordinate geometry to one H1+ and four O2- atoms. The K–H bond length is 2.56 Å. There are a spread of K–O bond distances ranging from 2.61–2.77 Å. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a distorted octahedral geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 2.01–2.14 Å. In the second Mg2+ site, Mg2+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (1.98 Å) and two longer (2.04 Å) Mg–O bond lengths. As5+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.74–1.92 Å. There are eleven inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a distorted linear geometry to one K1+ and two O2- atoms. There is one shorter (1.05 Å) and one longer (1.53 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.74 Å) H–O bond length. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the seventh H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.62 Å) H–O bond length. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the tenth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.52 Å) H–O bond length. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two H1+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one As5+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one As5+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to two H1+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one As5+, and one O2- atom. The O–O bond length is 1.44 Å. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Mg2+, one H1+, and one O2- atom. The O–O bond length is 1.50 Å. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a distorted water-like geometry to one Mg2+ and one O2- atom. The O–O bond length is 1.37 Å. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Mg2+, and one O2- atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two Mg2+, one H1+, and one O2- atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Mg2+, and two H1+ atoms. In the twelfth O2- site, O2- is bonded in a water-like geometry to one K1+ and two H1+ atoms.