Computational design of benzothiazole-derived push?pull dyes with high molecular quadratic hyperpolarizabilitiesElectronic supplementary information (ESI) available: Table S1: Heats of formation and relevant torsional angles (AM1) and ZINDO (gas phase and dioxane solution) dipole moments and ?vec-values for different conformations of compounds 1?51. Table S2: B3LYP/6-31G* energies, zero point energy corrections (au), torsional angles, DRRPA-HF/6-31G* and ZINDO (gas phase) hyperpolarizabilities for different conformations. Table S3: Contributions (two-state model, other configurations) to ZINDO gas phase hyperpolarizabilities (B3LYP/6-31G* lowest energy conformation). Table S4: Orbital energies and coefficients (2pz, 3pz) of the two highest occupied and two lowest virtual orbitals of pertinent model compounds. Table S5: Main configurations (gas phase, ZINDO, B3LYP/6-31G* geometry), wavenumbers ?, oscillator strengths f, and difference ?� of dipole moment for the first two electronic transitions (states). Table S6: Main configurations (gas phase, TDDFT/B3LYP/6-31G*//B3LYP/6-31G*), wavenumbers ? and oscillator strengths f for the first few electronic transitions (states) of compounds 1?4, 16, 42 and 48?50. Table S7: ZINDO SOS results (wavelength ?max of first absorption band (f > 0.1), dipole moment �, and ?vec-values for compounds 1?51 in the gas phase. See http://www.rsc.org/suppdata/cp/b3/b314150k/