class Coulomb : public feasst::ModelTwoBody

Compute energy between two point charges, \(q_i\) and \(q_j\) with a plain Coulomb potential.

\(U = q_i q_j \chi/r\)

where \(r\) is the separation distance, and \(\chi\) is the charge conversion factor assuming the following units:

  1. length: Angstroms

  2. energy: kJ/mol

  3. charge: elementary

Avoid singularity by returning a large, positive number when \(r\) is near zero.