text: Subtracting 
  long-range Coulombic potential 
  V LR 
  ij (r) (which depends on the dielectric constant of the 
  solvent) from V eﬀ 
  ij (r), we obtain the short-range contri- 
  bution V SR 
  ij (r) to the eﬀective potentials. These are given 
  in Fig. 1 (species 1 and 2 refer to Na+ and Cl− free ions, 
  respectively). All the short-range potentials exhibit os- 
  cillations corresponding to the solvent layering between 
  the ions, but this eﬀect is particularly important for the 
  cation-anion interaction: a considerable potential barrier 
  (& 2kBT ) separates the ﬁrst two attractive wells. To 
  serve as a reference, Monte Carlo (MC) simulations were 
  performed with these eﬀective potentials; a comparison 
  between MD and MC RDF is also provided in Fig. 1. The 
  excellent agreement between both sets of RDF validates 
  the HNC inversion procedure [17], and allows us to com- 
  
  the 