Symmetry handling in calculations of properties of atoms in molecules

Substantial savings in computational cost are realized upon the incorporation of symmetry handling into calculations of electronic properties of the quantum-mechanically defined atoms in molecules (AIMs). These savings are achieved by explicitly computing the properties of only those topological entities (AIMs, critical points, attractor interaction lines, etc.) that are symmetry-unique. Simple transformation formulae that relate properties of the symmetry-derived AIMs to those of the symmetry-unique ones are employed. The gains in computational performance that arise from the present implementation of symmetry handling are demonstrated with sample calculations on a variety of molecular systems treated at diverse levels of theory.