Figure 4.
Torsional parameters for methylated ammoniums. Lines = QM potential-energy plots. Symbols = AMOEBA energies for the corresponding conformations. C-N-CH torsion in dimethylammonium, RMSD = 0.07 kcal/mol; (blue line, triangle): CCNC torsion in dimethylammonium, RMSD = 0.13 kcal/mol; (green line, star): CCNC torsion in trimethylammonium, RMSD = 0.39 kcal/mol; (red line, square): CCNC in tetramethylammonium, RMSD = 0.40 kcal/mol (pink line, circle).