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+\documentclass[12pt]{article}
+
+\begin{document}
+
+\begin{eqnarray*}
+E(r_1,r_2, \ldots ,r_N) & = & \sum_{i,j} \phi_{i,j}(r_i,r_j) + 
+                              \sum_{ij} B_{i,j}(r_i,r_j) +
+                              \sum_{ijk} A_{i,j}(r_i,r_j,r_k) + \\
+                           && \sum_{ijkl} D_{i,j}(r_i,r_j,r_k,r_l) +
+                              \sum_{ijkl} I_{i,j}(r_i,r_j,r_k,r_l) +
+                              \sum_i F_i(r_i) 
+\end{eqnarray*}
+
+\end{document}
+