Effect of iron concentration on the crystallization and electronic structure of sphalerite/marmatite: A DFT study

In this work, various sphalerite crystal models with different iron (Fe) concentrations were selected for theoretical calculations to determine the influence rules of Fe concentration on the crystallization and electronic structure of sphalerite crystals. The results showed that with increasing Fe concentration, the lattice parameters generally gradually decreased. In other words, the crystal structure contracted slightly. Meanwhile, with the gradual decrease of the bond length between Fe and sulfur (S), the force between Fe and S slowly strengthened. The electrical conductivity of the crystals continuously rose and followed the changing trend from semi-conducting to semimetallic and then to metallic conductivity. Fe substitution induced obvious electron rearrangement, causing charge redistribution in the entire crystal structure. The Fe d orbital made a major contribution to the Fermi level.