First-principles self-consistent spin-polarized electronic structure calculations were performed for the nanoscale magnetic molecules ${\mathrm{Mn}}_{12}{\mathrm{O}}_{12}{(\mathrm{C}\mathrm{H}}_3{\mathrm{C}\mathrm{O}\mathrm{O})}_{16}{(\mathrm{H}}_2{\mathrm{O})}_4$ and ${\mathrm{Fe}}_{11}{\mathrm{O}}_6{\mathrm{}\left(\mathrm{OH}\right)\mathrm{}}_6{(\mathrm{O}}_2{\mathrm{C}\mathrm{P}\mathrm{h})}_{15}.$ The numerical discrete variational method was employed, within density-functional theory. Charges and magnetic moments were obtained for the atoms, as well as density of states diagrams, and charge- and spin-density maps. For ${\mathrm{Mn}}_{12}{\mathrm{O}}_{12}{(\mathrm{C}\mathrm{H}}_3{\mathrm{C}\mathrm{O}\mathrm{O})}_{16}{(\mathrm{H}}_2{\mathrm{O})}_4,$ values of the Heisenberg exchange parameters J were derived from the calculations; Mössbauer hyperfine parameters were calculated for ${\mathrm{Fe}}_{11}{\mathrm{O}}_6{\mathrm{}\left(\mathrm{OH}\right)\mathrm{}}_6{(\mathrm{O}}_2{\mathrm{C}\mathrm{P}\mathrm{h})}_{15}$ and compared to reported experimental values.

• Received 8 September 1998

DOI:https://doi.org/10.1103/PhysRevB.59.6927