Table 1.

Contains (from top to bottom) number of ions in each simulation, raw concentrations determined 20 Å beyond RNA (asterisk), concentrations corrected with a small potential perturbation approximation, and preferential interaction coefficients (Γ) obtained from the corrected concentrations.

	0 mM	0† mM	1 mM	6 mM	10 mM
N Mg2+	0	1	11	22	33
N K+	137	133	116	100	84
N Cl–	45	43	46	52	58
[Mg2+]*a	0.0 ± 0.0 mM	0.0 ± 0.0 mM	1.1 ± 0.9 mM	6.7 ± 2.6 mM	11.2 ± 1.6 mM
[K+]*	115.3 ± 2.6 mM	114.2 ± 1.6 mM	113.8 ± 1.9 mM	110.0 ± 4.9 mM	105.5 ± 2.7 mM
[Cl–]*	93.1 ± 1.8 mM	90.0 ± 1.1 mM	94.8 ± 1.2 mM	106.5 ± 1.4 mM	115.3 ± 0.7 mM
[Mg2+]b	0.0 ± 0.0 mM	0.0 ± 0.0 mM	0.9 ± 0.7 mM	5.8 ± 2.2 mM	10.2 ± 1.4 mM
[K+]	103.0 ± 2.0 mM	100.6 ± 1.2 mM	102.5 ± 1.7 mM	102.3 ± 4.6 mM	100.5 ± 2.5 mM
[Cl–]	103.0 ± 2.0 mM	100.6 ± 1.2 mM	104.2 ± 1.1 mM	113.9 ± 1.9 mM	120.8 ± 0.8 mM
Γ Mg2+	0.0 ± 0.0	1.0 ± 0.0	10.5 ± 0.4	18.7 ± 1.3	27.2 ± 0.8
Γ K+	78.0 ± 1.1	75.4 ± 0.7	57.3 ± 1.0	41.4 ± 2.6	26.5 ± 1.5
Γ Cl–	-14.0 ± 1.1	-14.6 ± 0.7	-13.7 ± 0.6	-13.2 ± 1.1	-11.2 ± 0.5

^aRaw concentration

^bCorrected concentration ∝ N – Γ