This user is new and incompetent and wants you to hit him up with some advice when he fucks up. He does his best to fix bad links, grammar but is too shy to design a sentence from scratch. Except these.
Can I make a Sandbox? Yes.
Fine.
ϕ n ( κ ) = 1 4 π 2 κ 2 ∫ 0 ∞ sin ( κ R ) κ R ∂ ∂ R [ R 2 ∂ D n ( R ) ∂ R ] d R {\displaystyle \phi _{n}(\kappa )={\frac {1}{4\pi ^{2}\kappa ^{2}}}\int _{0}^{\infty }{\frac {\sin(\kappa R)}{\kappa R}}{\frac {\partial }{\partial R}}\left[R^{2}{\frac {\partial D_{n}(R)}{\partial R}}\right]\mathrm {d} R}
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![{\displaystyle \phi _{n}(\kappa )={\frac {1}{4\pi ^{2}\kappa ^{2}}}\int _{0}^{\infty }{\frac {\sin(\kappa R)}{\kappa R}}{\frac {\partial }{\partial R}}\left[R^{2}{\frac {\partial D_{n}(R)}{\partial R}}\right]\mathrm {d} R}](https://wikimedia.org/api/rest_v1/media/math/render/svg/7e467c6b9d1f0f84335cb63ca310695fa0cd724d)