DOE OSTI2020
Ca6MnAl11 is Hexagonal Laves-derived structured and crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are twenty-four inequivalent Ca sites. In the first Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Mn and nine Al atoms. All Ca–Mn bond lengths are 3.34 Å. There are three shorter (3.21 Å) and six longer (3.32 Å) Ca–Al bond lengths. In the second Ca site, Ca is bonded in a 12-coordinate geometry to four Ca, three equivalent Mn, and nine Al atoms. There are one shorter (3.36 Å) and three longer (3.48 Å) Ca–Ca bond lengths. All Ca–Mn bond lengths are 3.35 Å. There are three shorter (3.22 Å) and six longer (3.29 Å) Ca–Al bond lengths. In the third Ca site, Ca is bonded in a 12-coordinate geometry to four Ca, three equivalent Mn, and nine Al atoms. There are one shorter (3.36 Å) and three longer (3.48 Å) Ca–Ca bond lengths. All Ca–Mn bond lengths are 3.35 Å. There are three shorter (3.22 Å) and six longer (3.29 Å) Ca–Al bond lengths. In the fourth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Mn and nine Al atoms. All Ca–Mn bond lengths are 3.34 Å. There are three shorter (3.21 Å) and six longer (3.32 Å) Ca–Al bond lengths. In the fifth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. All Ca–Ca bond lengths are 3.50 Å. There are a spread of Ca–Al bond distances ranging from 3.27–3.35 Å. In the sixth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. All Ca–Ca bond lengths are 3.50 Å. There are a spread of Ca–Al bond distances ranging from 3.27–3.35 Å. In the seventh Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. There are one shorter (3.38 Å) and three longer (3.48 Å) Ca–Ca bond lengths. There are a spread of Ca–Al bond distances ranging from 3.32–3.36 Å. In the eighth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. There are one shorter (3.34 Å) and three longer (3.50 Å) Ca–Ca bond lengths. There are nine shorter (3.29 Å) and three longer (3.37 Å) Ca–Al bond lengths. In the ninth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. There are one shorter (3.33 Å) and three longer (3.50 Å) Ca–Ca bond lengths. There are nine shorter (3.29 Å) and three longer (3.37 Å) Ca–Al bond lengths. In the tenth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. All Ca–Ca bond lengths are 3.48 Å. There are nine shorter (3.32 Å) and three longer (3.36 Å) Ca–Al bond lengths. In the eleventh Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. All Ca–Ca bond lengths are 3.48 Å. There are nine shorter (3.32 Å) and three longer (3.36 Å) Ca–Al bond lengths. In the twelfth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. All Ca–Ca bond lengths are 3.48 Å. There are nine shorter (3.32 Å) and three longer (3.36 Å) Ca–Al bond lengths. In the thirteenth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca and twelve Al atoms. There are a spread of Ca–Al bond distances ranging from 3.27–3.35 Å. In the fourteenth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. The Ca–Ca bond length is 3.37 Å. There are a spread of Ca–Al bond distances ranging from 3.26–3.33 Å. In the fifteenth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. The Ca–Ca bond length is 3.37 Å. There are a spread of Ca–Al bond distances ranging from 3.26–3.33 Å. In the sixteenth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca and twelve Al atoms. There are a spread of Ca–Al bond distances ranging from 3.27–3.36 Å. In the seventeenth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca and twelve Al atoms. There are a spread of Ca–Al bond distances ranging from 3.27–3.35 Å. In the eighteenth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca and twelve Al atoms. There are a spread of Ca–Al bond distances ranging from 3.27–3.36 Å. In the nineteenth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Mn and nine Al atoms. All Ca–Mn bond lengths are 3.35 Å. There are three shorter (3.26 Å) and six longer (3.29 Å) Ca–Al bond lengths. In the twentieth Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca, three equivalent Mn, and nine Al atoms. All Ca–Mn bond lengths are 3.34 Å. There are three shorter (3.22 Å) and six longer (3.29 Å) Ca–Al bond lengths. In the twenty-first Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Ca, three equivalent Mn, and nine Al atoms. All Ca–Mn bond lengths are 3.34 Å. There are three shorter (3.22 Å) and six longer (3.29 Å) Ca–Al bond lengths. In the twenty-second Ca site, Ca is bonded in a 12-coordinate geometry to three equivalent Mn and nine Al atoms. All Ca–Mn bond lengths are 3.35 Å. There are three shorter (3.25 Å) and six longer (3.29 Å) Ca–Al bond lengths. In the twenty-third Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. There are a spread of Ca–Al bond distances ranging from 3.31–3.35 Å. In the twenty-fourth Ca site, Ca is bonded in a 12-coordinate geometry to four Ca and twelve Al atoms. There are nine shorter (3.31 Å) and three longer (3.35 Å) Ca–Al bond lengths. There are four inequivalent Mn sites. In the first Mn site, Mn is bonded to six Ca and six Al atoms to form MnCa6Al6 cuboctahedra that share corners with three equivalent MnCa6Al6 cuboctahedra, corners with twelve AlCa6MnAl5 cuboctahedra, edges with six equivalent MnCa6Al6 cuboctahedra, and faces with nineteen AlCa6Al6 cuboctahedra. There are three shorter (2.75 Å) and three longer (2.79 Å) Mn–Al bond lengths. In the second Mn site, Mn is bonded to six Ca and six Al atoms to form MnCa6Al6 cuboctahedra that share corners with fifteen AlCa6Al6 cuboctahedra, edges with six equivalent MnCa6Al6 cuboctahedra, and faces with nineteen AlCa6Al6 cuboctahedra. There are three shorter (2.72 Å) and three longer (2.75 Å) Mn–Al bond lengths. In the third Mn site, Mn is bonded to six Ca and six Al atoms to form MnCa6Al6 cuboctahedra that share corners with fifteen AlCa6Al6 cuboctahedra, edges with six equivalent MnCa6Al6 cuboctahedra, and faces with nineteen AlCa6Al6 cuboctahedra. There are three shorter (2.72 Å) and three longer (2.75 Å) Mn–Al bond lengths. In the fourth Mn site, Mn is bonded to six Ca and six Al atoms to form MnCa6Al6 cuboctahedra that share corners with three equivalent MnCa6Al6 cuboctahedra, corners with twelve AlCa6Mn2Al4 cuboctahedra, edges with six equivalent MnCa6Al6 cuboctahedra, and faces with nineteen AlCa6Al6 cuboctahedra. There are three shorter (2.75 Å) and three longer (2.78 Å) Mn–Al bond lengths. There are twenty inequivalent Al sites. In the first Al site, Al is bonded to six Ca, one Mn, and five Al atoms to form AlCa6MnAl5 cuboctahedra that share corners with two equivalent MnCa6Al6 cuboctahedra, corners with sixteen AlCa6Al6 cuboctahedra, edges with six AlCa6Mn2Al4 cuboctahedra, faces with three equivalent MnCa6Al6 cuboctahedra, and faces with fifteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.79–2.86 Å. In the second Al site, Al is bonded to six Ca, one Mn, and five Al atoms to form AlCa6MnAl5 cuboctahedra that share corners with two equivalent MnCa6Al6 cuboctahedra, corners with sixteen AlCa6Al6 cuboctahedra, edges with six AlCa6Al6 cuboctahedra, faces with three equivalent MnCa6Al6 cuboctahedra, and faces with fifteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.79–2.86 Å. In the third Al site, Al is bonded to six Ca, one Mn, and five Al atoms to form AlCa6MnAl5 cuboctahedra that share corners with two equivalent MnCa6Al6 cuboctahedra, corners with sixteen AlCa6Al6 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, faces with three equivalent MnCa6Al6 cuboctahedra, and faces with fifteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.79–2.87 Å. In the fourth Al site, Al is bonded to six Ca, one Mn, and five Al atoms to form AlCa6MnAl5 cuboctahedra that share corners with two equivalent MnCa6Al6 cuboctahedra, corners with sixteen AlCa6Al6 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, faces with three equivalent MnCa6Al6 cuboctahedra, and faces with fifteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.79–2.87 Å. In the fifth Al site, Al is bonded to six Ca and six Al atoms to form a mixture of corner, edge, and face-sharing AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.77–2.93 Å. In the sixth Al site, Al is bonded to six Ca and six Al atoms to form AlCa6Al6 cuboctahedra that share corners with eighteen AlCa6Al6 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, and faces with eighteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.77–2.93 Å. In the seventh Al site, Al is bonded to six Ca, two Mn, and four equivalent Al atoms to form AlCa6Mn2Al4 cuboctahedra that share corners with four MnCa6Al6 cuboctahedra, corners with fourteen AlCa6MnAl5 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, faces with six MnCa6Al6 cuboctahedra, and faces with twelve AlCa6MnAl5 cuboctahedra. There are two shorter (2.85 Å) and two longer (2.86 Å) Al–Al bond lengths. In the eighth Al site, Al is bonded to six Ca, one Mn, and five Al atoms to form AlCa6MnAl5 cuboctahedra that share corners with two equivalent MnCa6Al6 cuboctahedra, corners with sixteen AlCa6Al6 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, faces with three equivalent MnCa6Al6 cuboctahedra, and faces with fifteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.81–2.90 Å. In the ninth Al site, Al is bonded to six Ca, one Mn, and five Al atoms to form AlCa6MnAl5 cuboctahedra that share corners with two equivalent MnCa6Al6 cuboctahedra, corners with sixteen AlCa6Al6 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, faces with three equivalent MnCa6Al6 cuboctahedra, and faces with fifteen AlCa6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.80–2.91 Å. In the tenth Al site, Al is bonded to six Ca and six Al atoms to form AlCa6Al6 cuboctahedra that share corners with eighteen AlCa6Al6 cuboctahedra, edges with six AlCa6MnAl5 cuboctahedra, and faces with eighteen AlCa6Al6 cuboctahedra. There are four shorter (2.85 Å) and two longer (2.87 Å) Al–Al bond lengths. In the eleventh Al site, Al is bonded to six Ca and six Al atoms to form a mixture of corner, edge, and face-sharing AlCa6Al6 cuboctahedra. There are four shorter (2.85 Å) and two longer (2.86 Å) Al–Al bond lengths. In the twelfth Al site, Al is bonded to six Ca and six Al atoms to form a mixture of corner, edge, and face-sharing AlCa6Al6 cuboctahedra. There are four shorter (2.85 Å) and two longer (2.86 Å) Al–Al bond lengths. In the thirteenth Al site, Al is bonded to six Ca and six Al atoms to form AlCa6Al6 cuboctahedra that share corners with three equivalent MnCa6Al6 cuboctahedra, corners with twelve AlCa6Al6 cuboctahedra, edges with six equivalent AlCa6Al6 cuboctahedra, and faces with nineteen AlCa6Al6 cuboctahedra. In the fourteenth Al site, Al is bonded to six Ca and six Al atoms to form AlCa6Al6 cuboctahedra that share corners with three equivalent MnCa6Al6 cuboctahedra, corners with twelve AlCa6Al6 cuboctahedra, edges with six equivalent AlCa6Al6 cuboctahedra, and faces with nineteen AlCa6Al6 cuboctahedra. In the fifteenth Al site, Al is bonded to six Ca and six Al atoms to form AlCa6Al6 cuboctahedra that share corners with fifteen AlCa6MnAl5 cuboctahedra, edges with six equivalent AlCa6Al6 cuboctahedra, a faceface with one MnCa6Al6 cuboctahedra, and faces with eighteen AlCa6MnAl5 cuboctahedra. In the sixteenth Al site, Al is bonded to six Ca an