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Remark on Dipole-Dipole Interaction

The interaction energy of two dipoles with distance vector \bgroup\color{col1}$ {\bf R}$\egroup,
$\displaystyle E^{\rm d-d}({\bf R})$ $\displaystyle =$ $\displaystyle \frac{{\bf d}_1 {\bf d}_{2}}{\vert{\bf R}\vert^3}-3
\frac{({\bf R} {\bf d}_1) ({\bf R}{\bf d}_{2}) }{\vert{\bf R}\vert^5}$ (2.8)

can alternatively be written as
$\displaystyle E^{\rm d-d}({\bf R})$ $\displaystyle =$ $\displaystyle -{\bf d}_1{\bf E}^{\rm dip}_2 = -{\bf d}_2{\bf E}^{\rm dip}_1,$ (2.9)

where \bgroup\color{col1}$ {\bf E}^{\rm dip}_2$\egroup is the electric field generated by dipole \bgroup\color{col1}$ 2$\egroup at the position of dipole \bgroup\color{col1}$ 1$\egroup, and vice versa.



Tobias Brandes 2005-04-26