Note that with the definition of the structure factor in eq. 4, this expression is only valid for the cross-and solvent-solvent terms. Lastly, while g lm (r) = g ml (r), the same is not true for S lm (q) and S ml (q), as N m and N l should also switch place, and thus we have not reduced the double sum further. In the following, we will use the shorthand index c to label the total cross-term scattering and structure factors, and v for the solvent-solvent term. Note that since the first term in eq. 3 is zero for I c (q), this term can be negative.