Materials Data on Ba2Na2SrAl4F20 by Materials Project

Na2Ba2SrAl4F20 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded in a 4-coordinate geometry to nine F1- atoms. There are a spread of Na–F bond distances ranging from 2.17–2.98 Å. Ba2+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Ba–F bond distances ranging from 2.70–3.04 Å. Sr2+ is bonded in a 10-coordinate geometry to six F1- atoms. There are a spread of Sr–F bond distances ranging from 2.52–2.56 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of Al–F bond distances ranging from 1.81–1.88 Å. In the second Al3+ site, Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of Al–F bond distances ranging from 1.79–1.88 Å. There are ten inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted linear geometry to one Na1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a 1-coordinate geometry to one Na1+, one Ba2+, one Sr2+, and one Al3+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to one Na1+, one Ba2+, one Sr2+, and one Al3+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Al3+ atom. In the fifth F1- site, F1- is bonded in a 1-coordinate geometry to two equivalent Na1+, one Sr2+, and one Al3+ atom. In the sixth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Al3+ atoms. In the seventh F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one Al3+ atom. In the eighth F1- site, F1- is bonded in a bent 150 degrees geometry to one Na1+ and two Al3+ atoms. In the ninth F1- site, F1- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Ba2+, and one Al3+ atom. In the tenth F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, two equivalent Ba2+, and one Al3+ atom.

Na₂Ba₂SrAl₄F₂₀结晶于单斜晶系P2₁/c空间群。该晶体为三维骨架结构。一价钠离子（Na⁺，Na1+）的配位几何为四配位，与九个氟离子（F⁻，F1-）成键，Na–F键长分布范围为2.17~2.98 Å。二价钡离子（Ba²⁺，Ba2+）的配位几何为十配位，与十个氟离子成键，Ba–F键长分布范围为2.70~3.04 Å。二价锶离子（Sr²⁺，Sr2+）的配位几何为十配位，与六个氟离子成键，Sr–F键长分布范围为2.52~2.56 Å。体系存在两种不等价的三价铝离子（Al³⁺，Al3+）位点：在第一种Al³⁺位点中，Al³⁺与六个氟离子成键，形成共顶连接的AlF₆八面体，共顶八面体的扭转角为31°，Al–F键长分布范围为1.81~1.88 Å；在第二种Al³⁺位点中，Al³⁺与六个氟离子成键，形成共顶连接的AlF₆八面体，共顶八面体的扭转角为31°，Al–F键长分布范围为1.79~1.88 Å。体系存在十种不等价的氟离子位点：第一种F⁻位点中，F⁻以畸变直线型配位几何与一个Na⁺和一个Al³⁺成键；第二种F⁻位点中，F⁻以单配位几何与一个Na⁺、一个Ba²⁺、一个Sr²⁺及一个Al³⁺成键；第三种F⁻位点中，F⁻以畸变单键型配位几何与一个Na⁺、一个Ba²⁺、一个Sr²⁺及一个Al³⁺成键；第四种F⁻位点中，F⁻以畸变单键型配位几何与两个等价的Ba²⁺及一个Al³⁺成键；第五种F⁻位点中，F⁻以单配位几何与两个等价的Na⁺、一个Sr²⁺及一个Al³⁺成键；第六种F⁻位点中，F⁻以畸变150°键角弯曲型配位几何与一个Na⁺及两个Al³⁺成键；第七种F⁻位点中，F⁻以畸变单键型配位几何与两个等价的Ba²⁺及一个Al³⁺成键；第八种F⁻位点中，F⁻以150°键角弯曲型配位几何与一个Na⁺及两个Al³⁺成键；第九种F⁻位点中，F⁻以四配位几何与一个Na⁺、两个等价的Ba²⁺及一个Al³⁺成键；第十种F⁻位点中，F⁻以二配位几何与一个Na⁺、两个等价的Ba²⁺及一个Al³⁺成键。