Electrostatic energy of two Gaussians of unit charge and unit spread calculated via exact real-space integration, reciprocal-space interaction with a single point countercharge (PCC), and reciprocal space intergration with a multiple PCC (the Makov-Payne correction). Gaussian charges are positioned at (–5,–5,–5) and (5,5,5), corresponding to a quadrupole moment of 153 a.u.Reuse & Permissions
Figure 2
Electrostatic energy of four Gaussians of unit charge and unit spread. Gaussian charges are positioned at (–5,–5,5), (–5,5,–5), (5,–5,–5), and (5,5,5), forming a tetrahedron and corresponding to a quadrupole moment of 306 a.u.Reuse & Permissions