. Author manuscript; available in PMC: 2021 Nov 10.

Published in final edited form as: J Chem Theory Comput. 2020 Oct 13;16(11):7184–7194. doi: 10.1021/acs.jctc.0c00847

Table 1.

Interaction Energies and Optimized Distances from ωB97X-D/6–311++G(d,p) Calculations, the OPLS/2020 Force Field, and Non-Polarizable OPLS-AA^a

π	cation	Conf.	ωB97X-D	R	OPLS/2020	R	OPLS-AA	R
benzene	Li⁺		−38.18	1.9	−39.44	1.7	−19.83	1.9
	Na⁺		−24.74	2.5	−25.30	2.3	−11.96	2.6
	K⁺		−18.32	2.9	−18.50	2.8	−8.33	3.1
	Rb⁺		−13.30	3.2	−13.17	3.0	−7.33	3.3
	Cs⁺		−11.60	3.4	−11.08	3.3	−6.24	3.5
	NH₄⁺	mono	−18.15	3.0	−19.41	3.0	−10.21	3.2
	NH₄⁺	bi	−18.80	3.0	−18.48	2.9	−10.41	3.0
	NMe₄⁺		−10.97	4.3	−9.47	4.2	−6.71	4.4
furan	_K⁺		−13.58	3.0	−14.39	2.9	−5.79	3.2
pyrrole	_K⁺		−20.16	2.9	−19.55	2.8	−10.52	3.0
thiophene	_K⁺		−15.91	3.0	−15.93	2.8	−8.25	3.1
pyridine	_K⁺		−13.50	3.0	−14.02	2.9	−7.86	3.1
pyrazine	_K⁺		−8.72	3.0	−8.02	2.9	−1.54	3.3
indole	_K⁺	π6	−23.57	2.8	−21.60	2.8	−9.49	3.1
	_K⁺	π5	−21.52	2.9	−18.58	3.2	−7.66	3.2
benzene	Gdm⁺	stacked	−7.98	3.5	−8.62	3.3	−4.83	3.4
	Gdm⁺	T-shaped	−14.50	4.0	−14.14	3.7	−10.02	3.8
indole	NH₄⁺	π6	−22.64	3.0	−21.13	2.9	−11.98	3.0
	NH₄⁺	π5	−19.48	3.0	−18.28	3.0	−10.28	3.0
indole	Gdm⁺	stacked	−13.17	3.3	−13.26	3.3	−7.94	3.4
	Gdm⁺	T-shaped	−17.71	4.0	−18.79	3.8	−13.65	3.9

Interaction energies in kcal/mol and optimized distances R in Å.