Abstract
In order to estimate the material property with sufficient accuracy and acceptable computational time using ab-initio calculation, the reduction of degrees of freedom required to approximate highly oscillated wave function around the nuclei is necessary. The curving-grid mesh which allocates a fine mesh around the nuclei seems effective for the reduction. We investigate the convergence property for ab-initio finite-element calculation with curving-grid mesh in terms of total energy. Through the calculation of an oxygen molecule, we found that the favorable convergence property, i.e. the variational convergence with the uniform rate, of the finite element method with uniform mesh is conserved. The application to bulk rock-salt magnesium oxide including 216 atoms shows the effectiveness of the curving-grid mesh in large-scale ab-initio calculation.
