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\begin{eqnarray*}
   R_{m}^{3} &=& \displaystyle\sum_{a}\displaystyle\sum_{b} x_{a}x_{b}R_{m,ab}^{3} \\
   \epsilon  &=& \frac{1}{R_{m}^{3}}\displaystyle\sum_{a}\displaystyle\sum_{b} x_{a}x_{b}\epsilon_{ab}R_{m,ab}^{3} \\
   \alpha    &=& \frac{1}{\epsilon R_{m}^{3}}\displaystyle\sum_{a}\displaystyle\sum_{b} x_{a}x_{b}\alpha_{ab}\epsilon_{ab}R_{m,ab}^{3} \\
\end{eqnarray*}                           

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