Table 1. Geometrical data for the H-bonds found with the NCI method.

Amino acids		Data				Method
Donor	Acceptor	HA (Å)	DA (Å)	D-HA (°)	Strength (a.u.)	1	2	3
Chain A – thiolate form
H2O	Glu48 Oε	1.72	2.67	174.0	−0.048	x	x	x
H2O	Glu48 Oε	1.88	2.77	152.6	−0.037	x
Arg116 Hη	H2O	2.01	2.90	146.7	−0.028	x		x
H2O	Glu48 Oε	2.13	2.99	149.3	−0.022	x		x
H2O	Arg116 Nη	2.15	3.10	169.3	−0.027
H2O	Cys45 Sγ	2.20	3.15	175.5	−0.030	x		x
Thr42 Hγ	Cys45 Sγ	2.29	3.18	153.2	−0.026	x		x
H2O	Cys45 Sγ	2.44	3.34	157.3	−0.022
H2O	Cys45 Sγ	2.49	3.45	176.6	−0.018
Chain B – thiolate form
Cys45 H	Cys45 Sγ	2.27	3.00	128.5	−0.031	x
Arg116 Hη	Cys 45 Sγ	2.30	3.22	151.3	−0.028	x
H2O	Cys45 Sγ	2.31	3.21	157.5	−0.024	x		x
Thr45 Hγ	Cys45 Sγ	2.33	3.18	146.5	−0.028	x
Arg116 Hη	Cys45 Sγ	2.45	3.33	146.8	−0.020
Chain A – thiol form
Cys45 Hγ	Leu39 O	1.80	3.03	152.1	−0.041	x		x
H2O	H2O	1.84	2.74	156.4	−0.037	x		x
Thr42 Hγ	H2O	1.90	2.84	168.1	−0.035	x	x	x
Arg116 Hη	H2O	1.98	2.92	155.7	−0.031	x		x
H2O	Thr42 Oγ	2.02	2.93	157.1	−0.026	x		x
H2O	Leu39 O	2.35	3.27	162.4	−0.016	x
Cys45 H	H2O	2.51	3.33	138.8	−0.012
H2O	Cys45 Sγ	2.77	3.22	109.4	−0.012
Chain B – thiol form
H2O	Thr42 Oγ	1.71	2.65	164.0	−0.052	x	x	x
Cys45 Hγ	Leu39 O	2.00	3.10	136.6	−0.028	x		x
Cys45 H	H2O	2.05	2.93	146.1	−0.026	x		x
Arg116 Hη	H2O	2.24	2.95	126.9	−0.018	x		x
Arg116 Hη	Cys45 Sγ	2.49	3.31	138.8	−0.018
Arg116 Hη	Cys45 N	2.57	3.33	132.3	−0.015
Arg116 Hη	Cys45 Sγ	2.95	3.65	130.9	−0.010

The distances HA and DA are in Å. The D-HA angle is in degrees (°). The strength [sign(λ₂)ρ] of the individual H-bonds provided by the NCI method are given in a.u. In the last three columns of the table, it is indicated whether the three conventional methods were able to find these H-bonds.