. Author manuscript; available in PMC: 2014 Mar 13.

Published in final edited form as: J Chem Theory Comput. 2013 Jan 9;9(3):1417–1427. doi: 10.1021/ct3010134

Table 2.

Comparison between analytic gradients and finite difference-computed gradients (kcal mol⁻¹ Å⁻¹) for a water dimer with coordinates (Å): O₁ (−6.302 51, 2.127 23, 0.823 74); H₁_a (−6.891 82, 2.556 39, 1.444 04); H₁_b (−5.736 54, 1.587 07, 1.3752 33); O₂ (−5.610 42, 3.122 60, − 1.661 72); H₂_a (−6.136 34, 2.539 42, −2.209 02); and H₂_b (−5.804 20, 2.830 43, −0.771 04).

	Analytic			Analytic-Numerical

	x	y	z	x	y	z
O₁	2.864 162	3.921 650	−7.135 612	0.000 000 03	0.000 000 10	0.000 000 00
H₁_a	0.105 627	−1.017 738	0.375 008	−0.000 000 12	−0.000 000 03	0.000 000 09
H₁_b	−0.983 719	−0.083 198	0.422 835	0.000 000 03	−0.000 000 03	0.000 000 02
O₂	−4.968 891	−6.631 666	10.682 508	−0.000 000 06	0.000 000 01	−0.000 000 24
H₂_a	1.082 556	1.367 119	−1.174 105	−0.000 000 05	−0.000 000 15	−0.000 000 01
H₂_b	1.900 265	2.443 833	−3.170 632	−0.000 000 08	0.000 000 03	0.000 000 28