TABLE 3.
Lennard-Jones interaction parameters of Na+ and K+ ions
| FFGMX
|
Åqvist
|
CHARMM
|
||||
|---|---|---|---|---|---|---|
| Ion | σ (nm) | ε (kJ mol−1) | σ (nm) | ε (kJ mol−1) | σ (nm) | ε (kJ mol−1) |
| Na+ | 0.25752 | 6.17743 × 10−2 | 0.33305 | 1.15980 × 10−2 | 0.24299 | 1.96290 × 10−1 |
| K+ | 0.64541 | 5.66508 × 10−5 | 0.49346 | 1.37235 × 10−3 | 0.35275 | 3.64251 × 10−1 |
The FFGMX parameters were obtained from the GROMACS package (22). We have also included Åqvist (59) and CHARMM parameters for comparison. The Åqvist parameters are reproduced from Chen et al. (33). The CHARMM parameters for Na+ are obtained from Gurtovenko et al. (20), and the modified CHARMM parameters for K+ are from Roux (60).