Variational projector augmented-wave method: theoretical analysis and preliminary numerical results
For researchers in electronic structure computation, this work offers an incremental improvement to the PAW method, enhancing plane-wave convergence.
The paper proposes and analyzes the variational projector augmented-wave (VPAW) method for Kohn-Sham electronic structure computations, which improves convergence with respect to the number of plane-waves compared to the standard PAW method. Numerical tests on an idealized case confirm this efficiency.
In Kohn-Sham electronic structure computations, wave functions have singularities at nuclear positions. Because of these singularities, plane-wave expansions give a poor approximation of the eigenfunctions. In conjunction with the use of pseudo-potentials, the PAW (projector augmented-wave) method circumvents this issue by replacing the original eigenvalue problem by a new one with the same eigenvalues but smoother eigenvectors. Here a slightly different method, called VPAW (variational PAW), is proposed and analyzed. This new method allows for a better convergence with respect to the number of plane-waves. Some numerical tests on an idealized case corroborate this efficiency.