The nuclear repulsion energy is a constant offset when we compute the total energy using any electronic structure method. This energy is a function of both the atomic charges and their geometry and is calculated from the classical electrostatic formula as:
The nuclear repulsion energy is a constant offset when we compute the total energy using any electronic structure method. This energy is a function of both the atomic charges and their geometry and is calculated from the classical electrostatic formula as:
$$ E{NN} = \sum{j > i} \frac{Z_i Z_j}{| \mathbf{R}_i - \mathbf{R}_j |} $$