Equation

[math]E=\frac{\sum_{i=1}^{m}k_{ET}^{(i)}}{\sum_{i=1}^{m}k_{ET}^{(i)}+k_{F}}[/math]

[math]k_{ET}^{(i)}=k_{F}\left ( \frac{R_{0}}{r} \right )^{6}[/math]

[math]E=\frac{R_{0}^{6}\sum_{i=1}^{m}i}{r^{6}+R_{0}^{6}\sum_{i=1}^{m}i}[/math]