Fig. 3: Stacking and solvent effects on energies of charge-transfer (CT) and locally excited (LE) states.
a The natural transition orbitals of the two LE and lowest CT state involved in the EET process. b The electron-hole distance77,78 in the Nic→Ade CT state in a representative stacked conformer depicted with a dashed line. The two dots specify the position of the center of charges of hole and electron created in the CT state. c Stacking Effect: Vertical transition energies of the CT state vs the electron-hole distance of the CT state in gas-phase. The black and green bands indicate the energies of Nic* and La state which show minimal fluctuation compared to CT state. The Gaussian profile shows the spread of the values of the CT state with FWHM of ca. 1 eV. Two structures with markedly different CT energies are highlighted with black dots for studying solvent effects. d, e Solvent Effect: The effect of the solvent fluctuations on the energies of the diabatic states for the two structures highlighted in (c), which represent respectively a case in which the CT is near degenerate with the La-state of Ade (d) and a case in which the CT state is significantly higher in energy (e). The two profiles were obtained by running an equilibrated solvent MD around the two frozen NADH solute geometry and computing vertical transition energies at XMS-CASPT2 level. Details in Suppl. Note. 14.
