氯化钠型结构Rock-salt structure

也可看作两套面心立方点阵（一套 Na⁺、一套 Cl⁻）沿晶胞棱方向错开半个边长相互穿插。NaCl 晶胞参数 a = 564 pm，Na–Cl 距离 282 pm。每个 Na⁺ 周围有 6 个 Cl⁻ 构成正八面体，次近邻是 12 个 Na⁺。空间群为 Fm3̄m，马德隆常数 1.7476。

It can also be viewed as two interpenetrating face-centred cubic lattices, one of Na⁺ and one of Cl⁻, offset by half a cell edge. For NaCl a = 564 pm and Na–Cl = 282 pm. Each Na⁺ has six Cl⁻ at the corners of a regular octahedron, with 12 Na⁺ as next-nearest neighbours. The space group is Fm3̄m and the Madelung constant 1.7476.

采用这一结构的化合物有：大多数碱金属卤化物（LiF–RbI，但 CsCl、CsBr、CsI 除外）、碱土金属氧化物和硫化物（MgO、CaO、SrO、BaO）、过渡金属氧化物（FeO、CoO、NiO、MnO）、AgCl、AgBr、PbS（方铅矿），以及 TiC、TiN 等间隙化合物。半径比 r⁺/r⁻ 一般在 0.414–0.732 之间。

Compounds with this structure include most alkali halides (LiF to RbI, but not CsCl, CsBr or CsI), alkaline-earth oxides and sulfides (MgO, CaO, SrO, BaO), transition-metal oxides (FeO, CoO, NiO, MnO), AgCl, AgBr, PbS (galena) and interstitial compounds such as TiC and TiN. Their radius ratios usually lie between 0.414 and 0.732.

1913 年 W. L. 布拉格用 X 射线衍射测定的第一批结构就包括 NaCl 和 KCl。KCl 中 K⁺ 与 Cl⁻ 散射能力相近，衍射图看起来像简单立方，这一对比帮助布拉格正确理解了 NaCl 型结构，并首次直接证明离子晶体中不存在单独的分子。

Among the first structures W. L. Bragg determined by X-ray diffraction in 1913 were NaCl and KCl. In KCl, K⁺ and Cl⁻ scatter X-rays almost equally, so its pattern looks simple cubic; the contrast helped Bragg understand the rock-salt structure correctly and gave the first direct proof that ionic crystals contain no separate molecules.