Table 7. Equilibrium Geometries and Ground-State Rotational Constants of Guanine at rev-DSDPBEP86/jun-cc-pVTZ and PW6B95/jul-cc-pVDZ Levels of Theory and upon LRA and TMA Augmentation and Comparison to the Experimental Rotational Constants^a.

	rev-DSDPBEP86	PW6B95	rev-DSDPBEP86-LRA	PW6B95-LRA	rev-DSDPBEP86-TMA	PW6B95-TMA
N1C2	1.3615	1.3563	1.3583	1.3587	1.3598	1.3583
C2N3	1.3205	1.3161	1.3174	1.3174	1.3158	1.3152
N3C4	1.3722	1.3668	1.3690	1.3693	1.3719	1.3750
C4C5	1.3889	1.3896	1.3863	1.3898	1.3809	1.3824
C4N6	1.3688	1.3616	1.3656	1.3640	1.3667	1.3644
C7N6	1.2990	1.2985	1.2960	1.2999	1.2948	1.2965
C7N8	1.3775	1.3732	1.3743	1.3759	1.3739	1.3746
N8C9	1.4089	1.4062	1.4056	1.4094	1.4038	1.4037
C9O10	1.2230	1.2221	1.2194	1.2217	1.2185	1.2193
C7N11	1.3814	1.3760	1.3781	1.3787	1.3781b	1.3787b
N1H12	1.0064	1.0066	1.0043	1.0032	1.0029	1.0024
C2H13	1.0789	1.0812	1.0724	1.0749	1.0776	1.0773
N8H14	1.0104	1.0099	1.0082	1.0065	1.0085	1.0083
N11H15	1.0094	1.0090	1.0072	1.0056	1.0072b	1.0056b
N11H16	1.0087	1.0087	1.0065	1.0053	1.0065b	1.0053b
N1C2N3	113.30	113.35	113.30c	113.35c	113.50	113.66
C2N3C4	104.52	104.62	104.50	104.37	104.32	104.28
N3C4C5	110.33	110.25	110.33	110.25	110.33	110.24
C5C4N6	124.37	124.32	124.37	124.32	124.31	124.33
C4N6C7	113.83	114.07	113.83	113.85	113.84	114.03
N6C7N8	124.68	124.43	124.68c	124.43c	124.80	124.53
C7N8C9	125.45	125.54	125.45	125.37	125.35	124.45
N8C9O10	121.65	121.36	121.65c	121.36c	121.92	121.56
N6C7N11	120.01	119.87	120.01c	119.87c	120.01c	119.87c
C2N1H12	127.76	127.74	127.51	127.76	127.60	127.64
N1C2H13	121.80	121.78	121.79	121.61	121.75	121.72
C7N8H14	119.58	119.80	119.35	119.81	119.59	119.76
C7N11H15	111.60	111.93	111.38	111.95	111.38b	111.95b
C7N11H16	116.19	116.76	115.97	116.77	115.97b	116.77b
N1C5C4N6	–179.49	–179.43	n.a.	n.a.	n.a.	n.a.
N3C4N6C7	179.29	179.35	n.a.	n.a.	n.a.	n.a.
C4N6C7N8	0.80	0.74	n.a.	n.a.	n.a.	n.a.
C4N6C7N11	–176.24	–176.37	n.a.	n.a.	n.a.	n.a.
N6C7N8H14	–175.11	–175.89	n.a.	n.a.	n.a.	n.a.
N8C7N11H15	170.60	170.74	n.a.	n.a.	n.a.	n.a.
H15C7N11H16	–131.62	–132.93	n.a.	n.a.	n.a.	n.a.
A	1911.495	1918.428	1921.161	1921.310	1922.995	1920.585
B	1116.019	1121.746	1121.377	1122.980	1121.366	1119.658
C	705.277	708.436	708.703	709.318	708.948	707.893
MAD %d	0.53	0.09	0.04	0.07	0.03	0.14

^aBond lengths in Å and angles in °. Rotational constants in MHz.

^bFrom the corresponding LRA.

^cNot parameterized, uncorrected value.

^dPercentage mean absolute deviation from experimental data:⁸⁶A = 1922.155 MHz, B = 1121.6840 MHz, C = 709.0079 MHz. Theoretical equilibrium rotational constants augmented by vibrational contributions evaluated at the PW6B95/jul-cc-pVDZ level: ΔA^vib = −11.662 MHz, ΔB^vib = −6.715 MHz, ΔC^vib = −4.227 MHz.