Electronic structure calculation for properties of Sn-based solder alloys with the relativistic DV-Xα method

The states of electronic structure formed through the interaction of atoms will essentially determine the properties of Sn-based solder alloys. Sn₂₈M (M=Cu, Zn, Ga, Ge, As, Ag, Cd, In, Sn, Sb, Au, Hg, Tl, Pb and Bi) cluster model, which was designed on the basis of the crystal structure of β-Sn, had been applied in the relativistic DV-Xα calculation. Some electronic structure parameters such as ionicity, electron density distribution, Mk (s orbital energy level beyond Fermi energy) and Bo (the orbital interaction) were obtained through the Mulliken analysis. Finally, relationships between electronic structure parameters and properties of Sn alloys were discussed, through which we can understand the properties of Sn-based solder alloys in a fundamental way.