Schematic representation of the simulation system. Imidazole and water molecules were treated quantum mechanically, and the carbon nanotube (CNT) was treated classically. External perturbations are created by electric fields generated by the charges on the CNT wall.
W4 proton-oxygen and W9 proton-nitrogen distances as a function of time in the nonperturbed system ; desolvation of the excess proton occurs at while protonation of the imidazole ring occurs at (total PT time); only the first of simulation are shown.
Location of the excess charge along the chain as a function of time for the unperturbed system . Arrows mark the approximate points where the charge reverses direction of motion; A and B show the final, fast charge transfer between the ends of the CNT over a distance of (see inset).
Atom-pair distances along the water chain as a function of time for the last prior to complete PT in the nonperturbed system (see inset in Fig. 2 for definitions): (a) , (b) , (c) , (d) , (e) , and (f) ; arrows A and B are as in Fig. 3.
Location of the excess charge along the chain as a function of time in perturbed systems . See Fig. 3 for details. Complete PT occurs for and proton blockage for .
Schematic representation of the structural defect ( on W7) induced on the water chain (for ). The distances a, b, and c and their fluctuations decrease as the perturbing field increases.
Oxygen-oxygen distance between water molecules W4 and W5 for the last of simulation in the nonperturbed system calculated with the 6-31G, , and basis sets. Lack of polarization shortens the O⋯O distances between contiguous water molecules, reflecting stronger water-water interactions along the chain. Introducing polarization on the hydrogen atoms and/or heavy atoms leads generally to larger O⋯O distances.
Location of the excess charge along the chain as a function of time in unperturbed systems for simulations using the (a) 6-31G and (b) basis sets. See Fig. 3 for additional details. Without polarization complete PT is not observed within the of the simulation [6-31G basis set in panel (a)].
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