Equation Icon  [ jk jl k l i jk jk i ij jk k jk ki j ] F i = ε6 − 15M-1-M-2-r12r12r12-+ 3M--1-M-2-r12− 3M-1-M-2-r12− 3M-1-M-2-r12 1SS r712 r512 r512 r512 = ε6-1- [15(⃗n ⋅⃗s )(⃗n ⋅⃗s )ni − 3si(⃗n ⋅⃗s ) − 3si(⃗n ⋅⃗s ) − 3ni (⃗s ⋅⃗s )], (224 ) r412 12 1 12 2 12 1 12 2 2 12 1 12 1 2