Geometric structures, electronic properties, and magnetism of M2Sn17(M = Ni, Mn) and their anions

The geometric structures and magnetism of the three probable isomers for Ni2Sn17 Mn2Sn17,[Ni2Sn17](4-) and [Mn2Sn17](2-) have been studied using the generalized gradient approximation based on density functional theory. It was found that the D-2d structures of Ni2Sn17, Mn2Sn17 [Ni2Sn17](4-) and [Mn2Sn17](2-) are the most stable structures among the three possible isomers. The study shows that the D-2d structure and the D-4d structure of Ni(2)Sn17 have spin-splitting, leading to the magnetic moment 4 mu(B) and 2 mu(B), respectively, and there is weak ferromagnetic interaction between the Ni and Sn atoms for the D2d Structure and the D-4d structure. However, there is no magnetic moment in the D-4h structure. On the other band, the D-2d, D-4d, and D-4h Mn2Sn17 have 2 mu(B), 6 mu(B) and 2 mu(B) magnetic moments, respectively. It is interesting that there is weak antiferromagnetic interaction and weak ferromagnetic interaction between Mn and Sn atoms for the D-2d and D-4h structures, respectively, while there is not only weak ferromagnetic interaction but also weak antiferromagnetic interaction between Mn and Sri atoms in the D-4d structure. Finally, It is worth noting that all their anion counterparts of [Ni2Sn17](4-) and [Mn2Sn17](2-) have closed electronic configurations, showing no magnetic moment.