Wavelets in all-electron density-functional calculations

We have developed an all-electron density-functional (AE-DF) program using the Mexican hat wavelet. The AE-DF program is applied to the ab initio all- electron calculations of small molecules as prototype systems, and the cons truction scheme of multiresolution support spheres is used to optimize the computational efficiency. Convergences are systematically demonstrated as a function of the number of resolution levels and support sphere sizes. Deta iled analyses of H-2, CO, and H2O molecules and the Is core-ionized C*O and CO* molecules show good agreement with experiments and other theoretical w orks. The results indicate that one can gain computational efficiency by se veral orders of magnitude over the plane-wave-based methods in these molecu les. [S0163-1829(99)00827-9].