Ca5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to two equivalent Bi(2) and three equivalent Bi(1) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one Bi(2) and four equivalent Bi(1) atoms. In the third Ca site, Ca(3) is bonded in a 5-coordinate geometry to one Bi(2) and four equivalent Bi(1) atoms. In the fourth Ca site, Ca(4) is bonded to one Bi(2) and four equivalent Bi(1) atoms to form distorted edge-sharing CaBi5 square pyramids. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 9-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), two equivalent Ca(4), and three equivalent Ca(1) atoms. In the second Bi site, Bi(2) is bonded in a 7-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), and four equivalent Ca(1) atoms.
Ca5Bi3 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to two equivalent Bi(2) and three equivalent Bi(1) atoms. There is one shorter (3.11 Å) and one longer (3.27 Å) Ca(1)-Bi(2) bond length. There are a spread of Ca(1)-Bi(1) bond distances ranging from 3.41-3.76 Å. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one Bi(2) and four equivalent Bi(1) atoms. The Ca(2)-Bi(2) bond length is 3.25 Å. There are two shorter (3.36 Å) and two longer (3.43 Å) Ca(2)-Bi(1) bond lengths. In the third Ca site, Ca(3) is bonded in a 5-coordinate geometry to one Bi(2) and four equivalent Bi(1) atoms. The Ca(3)-Bi(2) bond length is 3.14 Å. There are two shorter (3.36 Å) and two longer (3.50 Å) Ca(3)-Bi(1) bond lengths. In the fourth Ca site, Ca(4) is bonded to one Bi(2) and four equivalent Bi(1) atoms to form distorted edge-sharing CaBi5 square pyramids. The Ca(4)-Bi(2) bond length is 3.29 Å. There are two shorter (3.33 Å) and two longer (3.34 Å) Ca(4)-Bi(1) bond lengths. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 9-coordinate geometry to two equivalent Ca(2), two equivalent Ca(3), two equivalent Ca(4), and three equivalent Ca(1) atoms. In the second Bi site, Bi(2) is bonded in a 7-coordinate geometry to one Ca(2), one Ca(3), one Ca(4), and four equivalent Ca(1) atoms.