KBa4(FeAs)10 crystallizes in the tetragonal I4/m space group. K(1) is bonded in a body-centered cubic geometry to eight equivalent As(1) atoms. Ba(1) is bonded in a body-centered cubic geometry to two equivalent As(2) and six equivalent As(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one As(2) and three equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. In the second Fe site, Fe(2) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one K(1), three equivalent Ba(1), one Fe(2), and three equivalent Fe(1) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Ba(1) and four equivalent Fe(1) atoms.
KBa4(FeAs)10 crystallizes in the tetragonal I4/m space group. K(1) is bonded in a body-centered cubic geometry to eight equivalent As(1) atoms. All K(1)-As(1) bond lengths are 3.43 Å. Ba(1) is bonded in a body-centered cubic geometry to two equivalent As(2) and six equivalent As(1) atoms. Both Ba(1)-As(2) bond lengths are 3.46 Å. There are a spread of Ba(1)-As(1) bond distances ranging from 3.39-3.47 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one As(2) and three equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. The Fe(1)-As(2) bond length is 2.31 Å. There is one shorter (2.31 Å) and two longer (2.32 Å) Fe(1)-As(1) bond lengths. In the second Fe site, Fe(2) is bonded to four equivalent As(1) atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe(2)-As(1) bond lengths are 2.32 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to one K(1), three equivalent Ba(1), one Fe(2), and three equivalent Fe(1) atoms. In the second As site, As(2) is bonded in a 8-coordinate geometry to four equivalent Ba(1) and four equivalent Fe(1) atoms.