Peak position of Raman spectra for the OH stretching vibration of water at about 3400 cm⁻¹ as a function of the ratio of n/n_h for aqueous solutions of various electrolytes M · n H₂O. In panel (a) M refers to CaCl₂ (diamond), CaBr₂ (hexagon), Ca(ClO₄)₂ (triangle), MgCl₂ (circle), and AlCl₃ (square), and in panel (b) M refers to MgBr₂ (pentagon), Mg(ClO₄)₂ (triangle), LiCl^[25] (circle), and MnCl₂^[25] (square).