Materials Data on Na4Bi2O5 by Materials Project

Na4Bi2O5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 trigonal pyramids that share corners with two equivalent NaO4 trigonal pyramids, edges with two equivalent NaO5 square pyramids, and an edgeedge with one NaO4 trigonal pyramid. There are three shorter (2.32 Å) and one longer (2.34 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.48 Å. In the third Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 square pyramids that share corners with two equivalent NaO4 trigonal pyramids, an edgeedge with one NaO5 square pyramid, and edges with two equivalent NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.45–2.59 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 trigonal pyramids that share corners with two equivalent NaO5 square pyramids, corners with two equivalent NaO4 trigonal pyramids, and edges with two NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.33–2.50 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.09–2.91 Å. In the second Bi3+ site, Bi3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.10–2.15 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to five Na1+ and one Bi3+ atom to form distorted ONa5Bi octahedra that share edges with two equivalent ONa5Bi octahedra and edges with three equivalent ONa4Bi square pyramids. In the second O2- site, O2- is bonded to four Na1+ and one Bi3+ atom to form edge-sharing ONa4Bi square pyramids. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+ and two Bi3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one Bi3+ atom. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+ and two Bi3+ atoms.

Na₄Bi₂O₅结晶于单斜晶系P2₁/c空间群。该晶体结构为三维框架结构。体系中存在4个非等价的Na⁺配位位点。在第一个Na⁺配位位点中，Na⁺与4个O²⁻离子成键，形成NaO₄三角锥配位多面体；该多面体与2个等价的NaO₄三角锥共享顶点，与2个等价的NaO₅四方锥共享边，还与1个NaO₄三角锥共享一条边。此处Na-O键存在3条较短键长（2.32 Å）与1条较长键长（2.34 Å）。在第二个Na⁺配位位点中，Na⁺以畸变跷跷板型配位几何与4个O²⁻离子成键，Na-O键的键长分布范围为2.36~2.48 Å。在第三个Na⁺配位位点中，Na⁺与5个O²⁻离子成键，形成畸变NaO₅四方锥配位多面体；该多面体与2个等价的NaO₄三角锥共享顶点，与1个NaO₅四方锥共享一条边，还与2个等价的NaO₄三角锥共享边。此处Na-O键的键长分布范围为2.45~2.59 Å。在第四个Na⁺配位位点中，Na⁺与4个O²⁻离子成键，形成畸变NaO₄三角锥配位多面体；该多面体与2个等价的NaO₅四方锥共享顶点，与2个等价的NaO₄三角锥共享顶点，还与2个NaO₄三角锥共享边。此处Na-O键的键长分布范围为2.33~2.50 Å。体系中存在2个非等价的Bi³+配位位点。在第一个Bi³+配位位点中，Bi³+以畸变矩形跷跷板型配位几何与4个O²⁻离子成键，Bi-O键的键长分布范围为2.09~2.91 Å。在第二个Bi³+配位位点中，Bi³+以畸变三角非共面配位几何与3个O²⁻离子成键，Bi-O键的键长分布范围为2.10~2.15 Å。体系中存在5个非等价的O²⁻配位位点。在第一个O²⁻配位位点中，O²⁻与5个Na⁺和1个Bi³+原子成键，形成畸变ONa₅Bi八面体配位多面体；该多面体与2个等价的ONa₅Bi八面体共享边，还与3个等价的ONa₄Bi四方锥共享边。在第二个O²⁻配位位点中，O²⁻与4个Na⁺和1个Bi³+原子成键，形成具有边共享特征的ONa₄Bi四方锥配位多面体。在第三个O²⁻配位位点中，O²⁻以五配位几何与3个Na⁺和2个Bi³+原子成键。在第四个O²⁻配位位点中，O²⁻以四配位几何与3个Na⁺和1个Bi³+原子成键。在第五个O²⁻配位位点中，O²⁻以畸变矩形跷跷板型配位几何与2个Na⁺和2个Bi³+原子成键。