Electric dipole-dipole interaction
= Electric dipole-dipole interaction
Two point dipoles separated by $\mathbf r$ have interaction proportional to
$$
\frac{\mathbf p_1\cdot\mathbf p_2}{r^3}
-\frac{3(\mathbf p_1\cdot\mathbf r)(\mathbf p_2\cdot\mathbf r)}{r^5}.
$$
The formula combines the source <electric dipole> field with the second dipole's coupling to that field.