title: Topology of the spin-polarized charge density in bcc and fcc iron.
abstract: We report the first investigation of the topology of spin-polarized charge density, specifically in bcc and fcc iron. While the total spin-density is found to possess the topology of the non-magnetic prototypical structures, the spin-polarized charge densities of bcc and high-spin fcc iron are atypical. In these cases, the two spin densities are correlated: the spin-minority electrons have directional bond paths and deep minima, while the spin-majority electrons fill these holes, reducing bond directionality. The presence of distinct spin topologies allows us to show that the two phase changes seen in fcc iron (paramagnetic to low-spin and low-spin to high-spin) are different. The former follows the Landau symmetry-breaking paradigm and proceeds without a topological transformation, while the latter involves a topological catastrophe.
authors.affiliation: Molecular Theory Group, Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA. trjones@mines.edu
authors.forename: Travis E
authors.initials: TE
authors.lastname: Jones
authors.forename: Mark E
authors.initials: ME
authors.lastname: Eberhart
authors.forename: Dennis P
authors.initials: DP
authors.lastname: Clougherty