DOE OSTI2020
SrMgF4 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are six inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.48–2.73 Å. In the second Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Sr–F bond distances ranging from 2.42–2.68 Å. In the third Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.51–3.06 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Sr–F bond distances ranging from 2.42–2.76 Å. In the fifth Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Sr–F bond distances ranging from 2.45–2.98 Å. In the sixth Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Sr–F bond distances ranging from 2.47–2.66 Å. There are six inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 20–45°. There are a spread of Mg–F bond distances ranging from 1.94–2.07 Å. In the second Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 15–41°. There are a spread of Mg–F bond distances ranging from 1.98–2.03 Å. In the third Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 20–45°. There are a spread of Mg–F bond distances ranging from 1.96–2.07 Å. In the fourth Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 21–45°. There are a spread of Mg–F bond distances ranging from 1.97–2.07 Å. In the fifth Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 21–42°. There are a spread of Mg–F bond distances ranging from 1.97–2.04 Å. In the sixth Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 15–45°. There are a spread of Mg–F bond distances ranging from 1.94–2.06 Å. There are twenty-four inequivalent F1- sites. In the first F1- site, F1- is bonded to three Sr2+ and one Mg2+ atom to form distorted edge-sharing FSr3Mg tetrahedra. In the second F1- site, F1- is bonded in a 4-coordinate geometry to two Sr2+ and two Mg2+ atoms. In the third F1- site, F1- is bonded in a 4-coordinate geometry to three Sr2+ and one Mg2+ atom. In the fourth F1- site, F1- is bonded to three Sr2+ and one Mg2+ atom to form a mixture of distorted edge and corner-sharing FSr3Mg tetrahedra. In the fifth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Mg2+ atom. In the sixth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Sr2+ and two Mg2+ atoms. In the seventh F1- site, F1- is bonded in a 2-coordinate geometry to two Sr2+ and two Mg2+ atoms. In the eighth F1- site, F1- is bonded in a distorted T-shaped geometry to one Sr2+ and two Mg2+ atoms. In the ninth F1- site, F1- is bonded in a distorted trigonal planar geometry to two Sr2+ and one Mg2+ atom. In the tenth F1- site, F1- is bonded in a 4-coordinate geometry to three Sr2+ and one Mg2+ atom. In the eleventh F1- site, F1- is bonded in a 2-coordinate geometry to one Sr2+ and two Mg2+ atoms. In the twelfth F1- site, F1- is bonded in a 4-coordinate geometry to two Sr2+ and two Mg2+ atoms. In the thirteenth F1- site, F1- is bonded in a 2-coordinate geometry to one Sr2+ and two Mg2+ atoms. In the fourteenth F1- site, F1- is bonded in a 4-coordinate geometry to three Sr2+ and one Mg2+ atom. In the fifteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Sr2+ and two Mg2+ atoms. In the sixteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Sr2+ and two Mg2+ atoms. In the seventeenth F1- site, F1- is bonded in a 4-coordinate geometry to three Sr2+ and one Mg2+ atom. In the eighteenth F1- site, F1- is bonded in a 4-coordinate geometry to three Sr2+ and one Mg2+ atom. In the nineteenth F1- site, F1- is bonded in a distorted linear geometry to one Sr2+ and two Mg2+ atoms. In the twentieth F1- site, F1- is bonded in a 2-coordinate geometry to two Sr2+ and two Mg2+ atoms. In the twenty-first F1- site, F1- is bonded in a 3-coordinate geometry to two Sr2+ and one Mg2+ atom. In the twenty-second F1- site, F1- is bonded to three Sr2+ and one Mg2+ atom to form a mixture of distorted edge and corner-sharing FSr3Mg tetrahedra. In the twenty-third F1- site, F1- is bonded in a distorted T-shaped geometry to one Sr2+ and two Mg2+ atoms. In the twenty-fourth F1- site, F1- is bonded in a 4-coordinate geometry to three Sr2+ and one Mg2+ atom.