Materials Data on K2GaAs2 by Materials Project
K2GaAs2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six As+2.50- atoms. There are a spread of K–As bond distances ranging from 3.32–3.84 Å. In the second K1+ site, K1+ is bonded in a 5-coordinate geometry to five As+2.50- atoms. There are a spread of K–As bond distances ranging from 3.35–3.60 Å. In the third K1+ site, K1+ is bonded to six As+2.50- atoms to form a mixture of distorted edge and corner-sharing KAs6 octahedra. The corner-sharing octahedral tilt angles are 32°. There are a spread of K–As bond distances ranging from 3.52–3.75 Å. In the fourth K1+ site, K1+ is bonded in a 4-coordinate geometry to four As+2.50- atoms. There are a spread of K–As bond distances ranging from 3.29–3.45 Å. There are two inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded in a trigonal planar geometry to three As+2.50- atoms. There are two shorter (2.42 Å) and one longer (2.45 Å) Ga–As bond lengths. In the second Ga3+ site, Ga3+ is bonded in a trigonal planar geometry to three As+2.50- atoms. There are one shorter (2.41 Å) and two longer (2.44 Å) Ga–As bond lengths. There are four inequivalent As+2.50- sites. In the first As+2.50- site, As+2.50- is bonded in a 2-coordinate geometry to six K1+ and two Ga3+ atoms. In the second As+2.50- site, As+2.50- is bonded in a 7-coordinate geometry to five K1+, one Ga3+, and one As+2.50- atom. The As–As bond length is 2.49 Å. In the third As+2.50- site, As+2.50- is bonded in a 7-coordinate geometry to five K1+ and two Ga3+ atoms. In the fourth As+2.50- site, As+2.50- is bonded in a 1-coordinate geometry to five K1+, one Ga3+, and one As+2.50- atom.