Table I.

Counterpoise energies and basis set superposition errors for methylammonium ions interacting with benzene, after constrained optimization using the aug-cc-pVTZ without f functions basis set and M06−2X functional.

Initial Geometry	Counterpoise Energies (kcal/mol)
	NH4+	CH3NH3+	(CH3)2NH2+	(CH3)3NH+	(CH3)4N+
0_0	−19.0±0.1	−18.1±0.6	−17.0±0.7	−16.7±1.1	−8.8±0.7
30_0	−14.6±0.2	−14.0±0.1	−12.9±0.5	−12.7±0.7	−8.2±0.7
30_30	−15.1±0.0	−13.0±0.2	−12.9±0.6	−12.8±0.6	−8.1±0.7
60_0	−9.0±0.1	−8.5±0.2	−7.8±0.6	−7.5±0.7	−3.9±0.7
60_30	−9.0±0.1	−8.7±0.2	−7.9±0.6	−7.6±0.7	−3.9±0.7
90_0	−4.7±0.1	−4.1±0.2	−4.0±0.6	−3.9±0.6	0.5±0.1
90_30	−4.7±0.1	−4.3±0.2	−4.3±0.6	−3.8±0.5	−0.5±0.2