Table 3.

Water interaction energies (IE, kcal mol⁻¹) and minimum-energy distances (r, Å) for 1-methyluracil.

Interaction	QM		Drude-2013*		Drude-2017
	IE	r	IE	r	ΔIE	Δr
N1 oop	−0.10	2.34	−1.26	2.24	−1.26	2.24
C2 oop	−1.14	2.48	−1.29	2.44	−1.29	2.44
O2 oop	−3.82	2.06	−2.69	2.16	−2.69	2.16
O2 180	−4.30	2.02	−3.33	2.10	−3.33	2.10
O2 (N1)	−5.07	1.98	−3.65	2.00	−3.65	2.00
O2 (N3)	−5.40	1.92	−3.92	1.96	−3.92	1.96
N3 oop	−0.99	2.36	−1.24	2.28	−1.24	2.28
H3 180	−4.32	1.91	−4.82	1.86	−4.82	1.86
C4 oop	−1.70	2.52	−2.63	2.32	−2.63	2.32
O4 oop	−3.81	2.11	−4.35	2.10	−4.35	2.10
O4 180	−4.42	2.02	−4.73	2.05	−4.73	2.05
O4 (N3)	−5.90	1.90	−5.84	1.91	−5.84	1.91
O4 (C5)	−5.70	1.97	−4.90	2.09	−4.90	2.09
C5 oop	−1.49	2.45	−1.17	2.43	−1.17	2.43
H5 180	−1.95	2.26	−1.07	2.58	−1.07	2.58
C6 oop	−0.35	2.58	0.37	2.76	0.37	2.76
H6 180	−3.77	2.20	−6.82	2.12	−6.82	2.12
Avg. Diff. (all)			−0.14	−0.05	0.05	0.02
Abs. Avg. Diff. (all)			0.89	0.10	0.86	0.09
RMS Diff. (all)			1.15	0.14	1.14	0.12
Avg. Diff. (out-of-plane)			−0.13	−0.11	−0.11	−0.02
Abs. Avg. Diff. (out-of-plane)			0.66	0.13	0.65	0.09
RMS Diff. (out-of-plane)			0.77	0.15	0.75	0.11
Avg. Diff. (in-plane)			−0.14	0.00	0.19	0.05
Abs. Avg. Diff. (in-plane)			1.09	0.08	1.05	0.08
RMS Diff. (in-plane)			1.35	0.11	1.34	0.12

^*Some values obtained using the Drude-2013 differ from those reported by Baker et al.^[66] due to refinement, especially of internal terms, during the course of the development of the Drude-2013 DNA force field.^[39,40]