Abstract
Multiplets in a ligand field are treated within total-energy density-functional calculations by imposing density-matrix constraints on the -orbital occupation numbers consistent with the local site and state symmetries. We demonstrate the utility of this approach for the case of isolated Fe phthalocyanine (FePc) molecules with overall symmetry: We find three stationary states of , , and symmetries of the Fe ion, and total-energy calculations clearly demonstrate that the ground state is . By contrast, a columnar stacking of the FePc molecules (-FePc) is found to change the ground state to due to hybridization between adjacent molecules.
- Received 13 September 2011
DOI:https://doi.org/10.1103/PhysRevB.85.235129
©2012 American Physical Society