Materials Data on BaEu3 by Materials Project

BaEu3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ba is bonded to twelve Eu atoms to form BaEu12 cuboctahedra that share corners with six equivalent BaEu12 cuboctahedra, corners with twelve EuBa4Eu8 cuboctahedra, edges with eighteen EuBa4Eu8 cuboctahedra, faces with eight equivalent BaEu12 cuboctahedra, and faces with twelve EuBa4Eu8 cuboctahedra. There are six shorter (4.11 Å) and six longer (4.12 Å) Ba–Eu bond lengths. There are three inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent Ba and eight Eu atoms to form distorted EuBa4Eu8 cuboctahedra that share corners with four equivalent BaEu12 cuboctahedra, corners with fourteen equivalent EuBa4Eu8 cuboctahedra, edges with six equivalent BaEu12 cuboctahedra, edges with twelve EuBa4Eu8 cuboctahedra, faces with four equivalent BaEu12 cuboctahedra, and faces with sixteen EuBa4Eu8 cuboctahedra. There are six shorter (4.07 Å) and two longer (4.18 Å) Eu–Eu bond lengths. In the second Eu site, Eu is bonded to four equivalent Ba and eight Eu atoms to form distorted EuBa4Eu8 cuboctahedra that share corners with four equivalent BaEu12 cuboctahedra, corners with fourteen EuBa4Eu8 cuboctahedra, edges with six equivalent BaEu12 cuboctahedra, edges with twelve EuBa4Eu8 cuboctahedra, faces with four equivalent BaEu12 cuboctahedra, and faces with sixteen EuBa4Eu8 cuboctahedra. There are one shorter (4.07 Å) and one longer (4.18 Å) Eu–Eu bond lengths. In the third Eu site, Eu is bonded to four equivalent Ba and eight Eu atoms to form distorted EuBa4Eu8 cuboctahedra that share corners with four equivalent BaEu12 cuboctahedra, corners with fourteen EuBa4Eu8 cuboctahedra, edges with six equivalent BaEu12 cuboctahedra, edges with twelve EuBa4Eu8 cuboctahedra, faces with four equivalent BaEu12 cuboctahedra, and faces with sixteen EuBa4Eu8 cuboctahedra.

BaEu₃为类β-Cu₃Ti结构，结晶于六方晶系P6₃/mmc空间群。该结构为三维框架结构。钡（Ba）与12个铕（Eu）原子配位，形成BaEu₁₂立方八面体（cuboctahedra），该配位多面体与6个等价的BaEu₁₂立方八面体共享顶点，与12个EuBa₄Eu₈立方八面体共享顶点，与18个EuBa₄Eu₈立方八面体共享棱，与8个等价的BaEu₁₂立方八面体共享面，同时与12个EuBa₄Eu₈立方八面体共享面。Ba-Eu键长存在两种：6个较短键长为4.11 Å，6个较长键长为4.12 Å。
体系中存在3种不等价的Eu配位位点。
在第一种Eu位点中，Eu与4个等价的Ba原子和8个Eu原子配位，形成畸变的EuBa₄Eu₈立方八面体，该配位多面体与4个等价的BaEu₁₂立方八面体共享顶点，与14个等价的EuBa₄Eu₈立方八面体共享顶点，与6个等价的BaEu₁₂立方八面体共享棱，与12个EuBa₄Eu₈立方八面体共享棱，与4个等价的BaEu₁₂立方八面体共享面，同时与16个EuBa₄Eu₈立方八面体共享面。该位点的Eu-Eu键长存在两种：6个较短键长为4.07 Å，2个较长键长为4.18 Å。
在第二种Eu位点中，Eu与4个等价的Ba原子和8个Eu原子配位，形成畸变的EuBa₄Eu₈立方八面体，该配位多面体与4个等价的BaEu₁₂立方八面体共享顶点，与14个EuBa₄Eu₈立方八面体共享顶点，与6个等价的BaEu₁₂立方八面体共享棱，与12个EuBa₄Eu₈立方八面体共享棱，与4个等价的BaEu₁₂立方八面体共享面，同时与16个EuBa₄Eu₈立方八面体共享面。该位点的Eu-Eu键长存在两种：1个较短键长为4.07 Å，1个较长键长为4.18 Å。
在第三种Eu位点中，Eu与4个等价的Ba原子和8个Eu原子配位，形成畸变的EuBa₄Eu₈立方八面体，该配位多面体与4个等价的BaEu₁₂立方八面体共享顶点，与14个EuBa₄Eu₈立方八面体共享顶点，与6个等价的BaEu₁₂立方八面体共享棱，与12个EuBa₄Eu₈立方八面体共享棱，与4个等价的BaEu₁₂立方八面体共享面，同时与16个EuBa₄Eu₈立方八面体共享面。