Materials Data on BaErMn2O5 by Materials Project

BaErMn2O5 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, faces with four equivalent MnO5 square pyramids, and faces with four equivalent MnO5 trigonal bipyramids. There are four shorter (2.81 Å) and eight longer (3.21 Å) Ba–O bond lengths. Er3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Er–O bond lengths are 2.42 Å. There are two inequivalent Mn+2.50+ sites. In the first Mn+2.50+ site, Mn+2.50+ is bonded to five O2- atoms to form distorted MnO5 trigonal bipyramids that share corners with five equivalent MnO5 square pyramids and faces with four equivalent BaO12 cuboctahedra. There are one shorter (2.07 Å) and four longer (2.09 Å) Mn–O bond lengths. In the second Mn+2.50+ site, Mn+2.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with five equivalent MnO5 trigonal bipyramids and faces with four equivalent BaO12 cuboctahedra. There are four shorter (1.97 Å) and one longer (2.11 Å) Mn–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Er3+, and two Mn+2.50+ atoms. In the second O2- site, O2- is bonded to four equivalent Ba2+ and two Mn+2.50+ atoms to form a mixture of edge and corner-sharing OBa4Mn2 octahedra. The corner-sharing octahedral tilt angles are 2°.