Fast Atomic Charge Calculation for Implementation into a Polarizable Force Field and Application to an Ion Channel Protein

Table 1

Correlation coefficients () and standard deviations (SD) of the parameterization of the BPT charge calculation based on selected different charge models MPA (Mulliken population analysis), ESP (charges derived from electrostatic potentials), and NPA (natural population analysis) of the best and worst performing basis sets for each model. The overall best performance, NPA/6-31G(d,p), is marked in bold. ( is the total range of the charge distribution.)

Charge calculation model	Basis set	Correlation coefficient	Standard deviation; SD [e]	Relative standard deviation; SD/ [%]
MPA	STO-6G	0.9944	0.0244	10.50
	6-311^++G(d,p)	0.8182	0.1463	47.05
ESP	3-21G	0.9768	0.0818	20.90
	6-31^+G(d,p)	0.9414	0.1155	31.75
NPA	6-31G(d,p)	0.9967	0.0437	8.10
	6-311^+G(d,p)	0.9795	0.0959	19.69