         && - { \!\! \sum^{N}_{\begin{array}{c} {\scriptstyle l=0} \\ {\scriptstyle (l\neq j)}    \end{array} } \!\! }\frac{0}{\hbar}{ \!\! \sum_{\begin{array}{c} {\scriptstyle kn} \\ {\scriptstyle (k>0)}    \end{array} } \!\! }F_{