Linearized Augmented Plane-Wave and Muffin-Tin Orbital Method with the PBE Exchange–Correlation: Applied to Molecules from H2 through Kr2

Abstract

We show that we can efficiently calculate the atomization energies of homogeneous diatomic molecules from H2 through Kr2 within the convergence of chemical accuracy (\({\lesssim}1\) kcal/mol) using an all-electron full-potential linearized mixed-basis method which has recently been proposed by one of the authors, in the density functional calculations using the PBE exchange correlation functional. The method is unique compared with other mixed-basis methods in that we simultaneously use two kinds of augmented waves as bases in the framework of the linearized method: the augmented plane waves (APWs) and the muffin-tin orbitals (MTOs). These two bases are responsible for the efficient representation of extended nature and localized nature of wavefunctions. We use a new simple prescription to determine parameters of MTOs. Owing to the inclusion of the MTOs, we can attain the convergence of chemical accuracy only with a very small number of APWs (cutoff energy of APWs is typically \({\sim}4\) Ry).