We report on the crystal structures of three novel synthetic SrM-arsenates (M = Ni and Fe3+), isostructural or structurally related to the minerals from tsumcorite, carminite and brackebuschite groups. They were synthesised under mild hydrothermal conditions and further characterised using single-crystal X-ray diffraction (SXRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and Raman spectroscopy. SXRD and SEM-EDS yielded formulae: (I) SrNi2(AsO4)2⋅2H2O, (II) Sr1.4Fe3+1.6(AsO4)2(OH)1.6 and (III) SrFe3+(AsO4)(AsO3OH). All three structures are built up of slightly distorted MO6 octahedra and AsO4 tetrahedra that are linked by Sr2+ with different coordination geometries and hydrogen bonds. I represent a basic structure type typical for tsumcorite-group minerals (space group C2/m) while II has a new intermediate structure between carminite, PbFe3+2(AsO4)2(OH)2 and arsenbrackebuschite, Pb2Fe3+(AsO4)2(OH) (s.g. Pm). III is triclinic and adopts a new structure-type (s.g. P$\bar{1}$). The structure of I is built up of infinite linear edge-sharing NiO4(OH2)2 octahedral chains, extending along [010] and linked by AsO4 tetrahedra, SrO8 polyhedra and hydrogen bonds. The structure of II is characterised by the carminite-like FeO4(OH)2 octahedral chains and Edshammar-polyhedral chains, which involves SrO11 coordination polyhedra similar to that of PbO11 in arsenbrackebuschite. Both chains in II are aligned parallel to the b axis of the monoclinic unit cell and connected together by the arsenate AsO4 tetrahedra, SrO8 polyhedra and the hydrogen-bonding network. The compound III has a new type of crystal structure based on the unusual corrugated octahedral–tetrahedral-quadruple chains. These are made up of a central double-sided chain linked to two single-sided chains into a quadruple chain extended along the a axis. The chains in III are built up of FeO6 octahedra and AsO4 tetrahedra further linked to each other by shared vertices. The quadruple chains are interconnected by additional AsO4 tetrahedra forming a heteropolyhedral 3D open framework. Strontium atoms are situated in the two channels. The structural connections to related minerals and inorganic compounds are discussed.

我们报告了三种新型合成 Sr M -砷酸盐（M = Ni 和 Fe 3+）的晶体结构，与来自 tsumcorite、carminite 和 brackebuschite 组的矿物同构或结构相关。它们是在温和的水热条件下合成的，并使用单晶 X 射线衍射 (SXRD)、扫描电子显微镜与能量色散光谱 (SEM-EDS) 和拉曼光谱进一步表征。SXRD 和 SEM-EDS 得出以下公式： ( I ) SrNi 2 (AsO 4 ) 2 ⋅2H 2 O，( II ) Sr 1.4 Fe 3+ 1.6 (AsO 4 )2 (OH) 1.6和 ( III ) SrFe 3+ (AsO 4 )(AsO 3 OH)。所有三种结构都由略微扭曲的M O 6八面体和 AsO 4四面体组成，它们通过 Sr 2+以不同的配位几何形状和氢键连接。I代表了紫铜矿类矿物（空间群C 2/ m）的典型基本结构类型，而II具有介于胭脂红、PbFe 3+ 2 (AsO 4 ) 2 (OH) 2之间的新中间结构和砷化镁石，Pb 2 Fe 3+ (AsO 4 ) 2 (OH) (sg Pm )。III是三斜的，采用新的结构类型 (sg P $\bar{1}$ )。I的结构由无限线性边缘共享NiO 4 (OH 2 ) 2八面体链构成，沿[010]延伸并由AsO 4四面体、SrO 8多面体和氢键连接。II的结构特征为类胭脂红的FeO 4 (OH) 2八面体链和 Edshammar-多面体链，其中涉及 SrO 11配位多面体，类似于arsenbrackebuschite中 PbO 11 的配位多面体。II中的两条链都平行于单斜晶胞的b轴排列，并通过砷酸盐 AsO 4四面体、SrO 8多面体和氢键网络连接在一起。化合物III具有基于不寻常的波纹八面体-四面体-四重链的新型晶体结构。它们由一条中央双侧链与两条单侧链相连，形成一条沿a轴延伸的四重链。III 中的链由通过共享顶点进一步相互连接的 FeO 6八面体和 AsO 4四面体构成。四重链通过额外的 AsO 4四面体相互连接，形成一个杂多面体 3D 开放框架。锶原子位于两个通道中。讨论了与相关矿物和无机化合物的结构联系。