Table 3. Evolution of Structure and the QM/MM-Derived νFeHis of the Deligated α and β Subunits during the PELE Simulation.

	α chain					β chain
step	νFeHisa	db	θc	RMSDTd	RMSDRe	νFeHisa	db	θc	RMSDTd	RMSDRe
R*	223	2.132	92.0	–	–	220	2.140	92.3	–	–
R	213	2.198	94.6	1.59	0.00	215	2.194	96.4	3.68	0.00
1	210	2.212	99.4	1.62	0.77	213	2.191	100.7	3.77	0.84
10	205	2.233	102.1	1.48	0.74	203	2.201	96.9	3.67	0.88
20	200	2.232	104.5	1.46	0.93	204	2.199	100.0	3.68	0.94
30	199	2.234	103.2	1.53	0.87	204	2.200	98.8	3.70	0.80
40	201	2.218	102.4	1.46	0.88	205	2.209	98.4	3.65	0.90
50	195	2.251	105.0	1.45	0.89	206	2.199	101.0	3.69	0.82
T	197(2)	2.24(1)	102(2)	0.00	1.59	204(2)	2.21(1)	102(2)	0.00	3.68

^aFe–His stretching frequency (cm^–1).

^bFe–His bond length (Å).

^cHeme-His tilting angle (“C” pyrrole nitrogen–iron–His Nε angle in degrees).

^dRMSD of α carbon displacements (Å) between the PELE intermediate and the deoxyHb crystal structure (1A3N)⁸ for the α₁ (left) or β₁ (right) subunits.

^eRMSD of α carbon displacements (Å) between the PELE intermediate and the initial R structure for the α₁ (left) or β₁ (right) subunits.