. Author manuscript; available in PMC: 2008 Jun 23.

Published in final edited form as: J Am Chem Soc. 2003 Nov 12;125(45):13804–13818. doi: 10.1021/ja035654x

Table 3.

Stark Effect Dephasing Contributions from MD Simulations^a

	R_ε state		B_ε state
	Stark frequency shift (cm⁻¹)	FFCF (t = 0) ((rad/ps)²)	Stark frequency shift (cm⁻¹)	FFCF (t = 0) ((rad/ps)²)
all	−48.8	9.35	−29.6	2.80
protein	−51.7	8.45	−31.4	2.12
His64	−6.7	7.75	14.0	1.03
solvent	2.8	2.01	1.8	1.93

The Stark effect frequency shift contributions and initial amplitudes of the FFCFs for various parts of the protein and solvent for the N_ε–H tautomer simulations. The differences in the average frequencies for B_ε and R_ε are almost entirely due to the electric field contribution of His64. The Stark effect frequency shift and the initial amplitudes of the FFCF for the solvent are essentially the same. The Stark frequency shifts are additive; the initial amplitudes of the FFCFs are not.