Property‐Optimized Gaussian Atomic Orbitals

Abstract
Property‐optimized Gaussian expansions of 1s‐, 2s‐, and 2p‐Slater‐type orbitals are obtained by weighting the usual fittings with r−2, r−1, r and r2. Pseudonormalized expectation values of r−2, r−1, r, r2, and 122 calculated with the very small‐term expansions are of exceptional quality by comparison with the values calculated with unweighted expansions.