Table 5:

Number of DNA-associated sodium ions, in simulations of the mixed sequence DNA obtained using different solvent models. Standard errors of the mean are indicated. Agreement with experiment⁵⁸ improves in the order: SPC/E+J/C, TIP3P+J/C, OPC+J/C, OPC+L/M HFE. Deviation from experiment is the largest for SPC/E+J/C. The experimental numbers were scaled to account for the 1 b.p. difference in length between the DNA fragment used in the experiment and that used in our simulation, see Methods.

Bulk salt concentration (M)	0.15	0.5
SPC/E+J/C	42.1 ± 0.5	38.1 ± 0.5
TIP3P+J/C	37.5 ± 0.5	32.6 ± 0.5
OPC+J/C	37.7 ± 0.5	33.0 ± 0.5
OPC+L/M HFE	38.4 ± 0.5	34.0 ± 0.5
Experiment	37 ± 2	35 ± 3