DOE OSTI2020
Na3Ti is Uranium Silicide-like structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are six inequivalent Na sites. In the first Na site, Na is bonded to eight Na and four Ti atoms to form distorted NaNa8Ti4 cuboctahedra that share corners with four equivalent TiNa12 cuboctahedra, corners with fourteen NaNa8Ti4 cuboctahedra, edges with six TiNa12 cuboctahedra, edges with twelve NaNa8Ti4 cuboctahedra, faces with four TiNa12 cuboctahedra, and faces with sixteen NaNa8Ti4 cuboctahedra. There are a spread of Na–Na bond distances ranging from 3.49–3.58 Å. There are a spread of Na–Ti bond distances ranging from 3.49–3.52 Å. In the second Na site, Na is bonded to eight Na and four Ti atoms to form distorted NaNa8Ti4 cuboctahedra that share corners with four equivalent TiNa12 cuboctahedra, corners with fourteen NaNa8Ti4 cuboctahedra, edges with six TiNa12 cuboctahedra, edges with twelve NaNa8Ti4 cuboctahedra, faces with four TiNa12 cuboctahedra, and faces with sixteen NaNa8Ti4 cuboctahedra. There are a spread of Na–Na bond distances ranging from 3.46–3.55 Å. There are three shorter (3.52 Å) and one longer (3.53 Å) Na–Ti bond lengths. In the third Na site, Na is bonded to eight Na and four Ti atoms to form distorted NaNa8Ti4 cuboctahedra that share corners with four equivalent TiNa12 cuboctahedra, corners with fourteen NaNa8Ti4 cuboctahedra, edges with six TiNa12 cuboctahedra, edges with twelve NaNa8Ti4 cuboctahedra, faces with four TiNa12 cuboctahedra, and faces with sixteen NaNa8Ti4 cuboctahedra. There are two shorter (3.54 Å) and two longer (3.55 Å) Na–Na bond lengths. There are two shorter (3.51 Å) and two longer (3.54 Å) Na–Ti bond lengths. In the fourth Na site, Na is bonded to eight Na and four Ti atoms to form distorted NaNa8Ti4 cuboctahedra that share corners with four equivalent TiNa12 cuboctahedra, corners with fourteen NaNa8Ti4 cuboctahedra, edges with six TiNa12 cuboctahedra, edges with twelve NaNa8Ti4 cuboctahedra, faces with four TiNa12 cuboctahedra, and faces with sixteen NaNa8Ti4 cuboctahedra. There are a spread of Na–Na bond distances ranging from 3.47–3.59 Å. There are a spread of Na–Ti bond distances ranging from 3.49–3.52 Å. In the fifth Na site, Na is bonded to eight Na and four Ti atoms to form distorted NaNa8Ti4 cuboctahedra that share corners with four equivalent TiNa12 cuboctahedra, corners with fourteen NaNa8Ti4 cuboctahedra, edges with six TiNa12 cuboctahedra, edges with twelve NaNa8Ti4 cuboctahedra, faces with four TiNa12 cuboctahedra, and faces with sixteen NaNa8Ti4 cuboctahedra. There are one shorter (3.44 Å) and one longer (3.55 Å) Na–Na bond lengths. There are a spread of Na–Ti bond distances ranging from 3.51–3.53 Å. In the sixth Na site, Na is bonded to eight Na and four Ti atoms to form distorted NaNa8Ti4 cuboctahedra that share corners with four equivalent TiNa12 cuboctahedra, corners with fourteen NaNa8Ti4 cuboctahedra, edges with six TiNa12 cuboctahedra, edges with twelve NaNa8Ti4 cuboctahedra, faces with four TiNa12 cuboctahedra, and faces with sixteen NaNa8Ti4 cuboctahedra. There are two shorter (3.51 Å) and two longer (3.54 Å) Na–Ti bond lengths. There are two inequivalent Ti sites. In the first Ti site, Ti is bonded to twelve Na atoms to form TiNa12 cuboctahedra that share corners with six equivalent TiNa12 cuboctahedra, corners with twelve NaNa8Ti4 cuboctahedra, edges with eighteen NaNa8Ti4 cuboctahedra, faces with eight TiNa12 cuboctahedra, and faces with twelve NaNa8Ti4 cuboctahedra. In the second Ti site, Ti is bonded to twelve Na atoms to form TiNa12 cuboctahedra that share corners with six equivalent TiNa12 cuboctahedra, corners with twelve NaNa8Ti4 cuboctahedra, edges with eighteen NaNa8Ti4 cuboctahedra, faces with eight TiNa12 cuboctahedra, and faces with twelve NaNa8Ti4 cuboctahedra.