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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaTc3 by Materials Project

NaTc3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Na1+ is bonded in a distorted body-centered cubic geometry to fourteen Tc+0.33- atoms. There are eight shorter (2.70 Å) and six longer (3.11 Å) Na–Tc bond lengths. There are two inequivalent Tc+0.33- sites. In the first Tc+0.33- site, Tc+0.33- is bonded to four equivalent Na1+ and four equivalent Tc+0.33- atoms to form a mixture of distorted face, edge, and corner-sharing TcNa4Tc4 tetrahedra. All Tc–Tc bond lengths are 2.70 Å. In the second Tc+0.33- site, Tc+0.33- is bonded in a 8-coordinate geometry to six equivalent Na1+ and eight equivalent Tc+0.33- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na3Tc by Materials Project

Na3Tc is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four equivalent Tc3- atoms to form NaTc4 tetrahedra that share corners with twelve equivalent NaTc6 octahedra, corners with sixteen equivalent NaTc4 tetrahedra, edges with six equivalent NaTc4 tetrahedra, and faces with four equivalent NaTc6 octahedra. The corner-sharing octahedral tilt angles are 55°. All Na–Tc bond lengths are 3.28 Å. In the second Na1+ site, Na1+ is bonded to six equivalent Tc3- atoms to form NaTc6 octahedra that share corners with six equivalent NaTc6 octahedra, corners with twenty-four equivalent NaTc4 tetrahedra, edges with twelve equivalent NaTc6 octahedra, and faces with eight equivalent NaTc4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. All Na–Tc bond lengths are 3.78 Å. Tc3- is bonded in a body-centered cubic geometry to fourteen Na1+ atoms.

36 MATERIALS SCIENCE↗