DOE OSTI2020
Bi4O5F2 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are eight inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 8-coordinate geometry to seven O2- and one F1- atom. There are a spread of Bi–O bond distances ranging from 2.27–2.99 Å. The Bi–F bond length is 2.73 Å. In the second Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to five O2- and one F1- atom. There are a spread of Bi–O bond distances ranging from 2.22–2.61 Å. The Bi–F bond length is 2.36 Å. In the third Bi3+ site, Bi3+ is bonded in a rectangular see-saw-like geometry to three O2- and one F1- atom. There are a spread of Bi–O bond distances ranging from 2.11–2.15 Å. The Bi–F bond length is 2.62 Å. In the fourth Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.21–2.93 Å. In the fifth Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to four O2- and one F1- atom. There are a spread of Bi–O bond distances ranging from 2.23–2.30 Å. The Bi–F bond length is 2.67 Å. In the sixth Bi3+ site, Bi3+ is bonded in a distorted rectangular see-saw-like geometry to three O2- and one F1- atom. There are a spread of Bi–O bond distances ranging from 2.11–2.14 Å. The Bi–F bond length is 2.69 Å. In the seventh Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to five O2- and one F1- atom. There are a spread of Bi–O bond distances ranging from 2.19–2.69 Å. The Bi–F bond length is 2.34 Å. In the eighth Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to four O2- and two F1- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.36 Å. There are one shorter (2.47 Å) and one longer (2.96 Å) Bi–F bond lengths. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Bi3+ atoms. In the second O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to four Bi3+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to four Bi3+ atoms. In the sixth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the seventh O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Bi3+ atoms. In the ninth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the tenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted L-shaped geometry to two Bi3+ atoms. In the second F1- site, F1- is bonded in an L-shaped geometry to two Bi3+ atoms. In the third F1- site, F1- is bonded in an L-shaped geometry to two Bi3+ atoms. In the fourth F1- site, F1- is bonded in a 1-coordinate geometry to two Bi3+ atoms.