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Electrostatic potentials

In an analogous way electrostatic potentials can be calculated on grids.

$pointval pot

leads to calculation of the electrostatic potential of electrons and nuclei (and external constant electric fields and point charges Q if present).

V($\displaystyle \vec{{R}}_{P}^{}$) = - $\displaystyle \int$$\displaystyle {\frac{{\rho(\vec{r})}}{{r_{Pr}}}}$d3$\displaystyle \vec{{r}}\,$ + $\displaystyle \sum_{{A}}^{}$$\displaystyle {\frac{{Z_A}}{{R_{PA}}}}$ + $\displaystyle \Big($$\displaystyle \vec{{R}}_{P}^{}$$\displaystyle \vec{{E}}\,$ + $\displaystyle \sum_{{Q}}^{}$$\displaystyle {\frac{{Q}}{{R_{PQ}}}}$$\displaystyle \Big)$ (13.2)

In order to prevent the calculation of singularities at the positions of nuclei, for gridpoints that are closer to a nucleus than 10-6 a.u. the charge of the respective nucleus is omitted in the calculation of the electrostatic potential for these points. The output files are termed tp.plt, sp.plt, etc.