To what extent of ion neutralization can multivalent ion distributions around RNA-like macroions be described by Poisson

To what extent of ion neutralization can multivalent ion distributions around RNA-like macroions be described by Poisson–Boltzmann theory?

Xiong Gui, Xi Kun, Zhang Xi^†, Tan Zhi-Jie^‡

(color online) (a)–(c) Net ion charge distribution Q(r) obtained from PB theory (dashed lines) and MC simulations (solid lines) around a 58-nt rRNA fragment (PDB code: 1HC8) in divalent salt solutions. (d)–(f) Deviations between distributions Q(r) of PB theory and MC simulations. Distributions Q(r) and deviations for other RNAs and DNAs in divalent salt solutions can be found in Fig. S7 in the supplementary material.