. Author manuscript; available in PMC: 2015 Nov 3.

Published in final edited form as: J Chem Theory Comput. 2014 Mar 11;10(3):1150–1163. doi: 10.1021/ct400988e

Table 3.

Lennard-Jones parameters (ion-oxygen) for FQ simulations of ions in water.

LJ	Na1	Na2	Na3	Na4	Ca²⁺ fix.	Ca²⁺ FQ	La³⁺ fix.	La³⁺ FQ
σ (Å)	2.8900	2.8900	2.5000	1.7500	3.1600	2.8000	3.7500	3.1500
ε (kJ/mol)	0.0628	0.0628	0.0628	10.460	0.5060	0.5060	0.2150	0.3350

Lennard-Jones parameters used with fixed and fluctuating charge simulations for the three ion-water systems studied. Note that the force field definitions and combination rules are different between GROMOS (used for Na⁺ and Ca²⁺ in combination with SPC or SPC-FQ2) and OPLS (used for La³⁺ in combination with TIP3P or TIP3P-FQ2). The four simulation performed for Na+ have labeled Na1 (fixed charges), Na2 (FQ), Na3 (FQ), Na4 (FQ). For Ca²⁺ and La³⁺ trajectories with fixed and fluctuating charges have been indicated with either “fix.” or FQ.