Calculations of the electronic structure of 3d transition metal dimers with projector augmented plane wave method

The projected augmented plane wave method provides an all-electron solution to the Kohn-Sham local density approximation to the electronic Schrodinger equation. By projecting the fast-varying parts of the single-particle orbitals onto a local basis it allows accurate calculations for molecules and solids throughout the periodic table using a plane wave basis without the introduction of pseudopotentials. The method, thereby, preserves the efficiency required for applications to first-principles molecular dynamics simulations, while still allowing an unambiguous solution for systems containing strong scattering atoms such as transition metals. In this work, we made a comprehensive comparison of the structural and energetic properties of homonuclear 3d transition metal diatomic molecules as predicted by projector augmented plane wave and by various local basis methods. These molecules are particularly difficult to treat with plane-wave pseudopotential methods. The bond energies, bond lengths, and vibrational frequencies for the lowest-lying multiplet states are calculated. Our results demonstrate that projector augmented plane wave calculations deliver the same level of accuracy as local basis methods. (C) 2003 American Institute of Physics.