TD-B3LYP

Figure 2-3. Protonated Schiff-base of retinal (PSBR) and computational models used in ONIOM QM QM calculations (left). Electrostatic effects of the surrounding protein on excitation energies in bacteriorhodopsin evaluated using TD-B3LYP Amber right). (Adapted from Vreven and Morokuma [37] (Copyright American Institute of Physics) and Vreven et al. [38], Reprinted with permission.)...

As shown by the calculations of bacteriorhodopsin (Section 2.3.2.1), ONIOM is an excellent tool for excited-state reactions in biology. The important rhodopsin system has been studied both by TD-B3LYP Amber [80] and CASSCF Amber [81]. Another example of the combination of CASSCF with Amber for the surrounding protein can be found for the yellow protein [82],... 

The UV-Vis spectra of the deep purple methanoUc solution of alkali DNM salts exhibit one very strong characteristic Tt Ji and two weak n tt electronic transitions at ca 331, 503 and 679 nm, respectively, which could be assigned on the basis of TD-B3LYP calculation (Figure 13, Table 6). The purple color arises from the two weak n tt electronic transitions . ... 

Figure 11.1. Differential electronic absorption spectra produced by irradiation of CF3N3 in an Ar matrix at 12 K with 254-nm light of 5 min (1), 25 min (2) and 45 min, (3) duration. The calculated absorption bands (TD-B3LYP/6-31 ) of triplet CF3N (positive) and CF3N3 (negative) are depicted as soUd vertical lines. [Reproduced with permission from N. P. Gritsan, I. Likhotvorik, Z. Zhendog, and M. S. Platz, J. Phys. Chem. A 2001, 105, 3039.]...

With respect to emission, tire geometry computed for the excited-state Alq3 structure at the CIS/3-21-I-G level was found to be significantly different from that for the ground state. This leads to a Stokes shift of 0.8 eV, which is not particularly well reproduced at the CIS level but is quite accurately predicted at the TD-B3LYP level. 

Cluster Transition character TD-B3LYP EOM-CCSD MRDCI Exp. 

System Transition from TD-B3LYP CASPT2 MRDCI OVGF Exp. 

In the Si(OX)3 cluster, which simulates a surface E -center in bulk silica, two lowest in energy electronic transitions occur from MOs combined of oxygen lone pairs to the singly occupied sp3-hybrid-type orbital of Si. In this case, the TD-B3LYP result (4.66 eV) underestimates the experimental value by 1.5eV, while the OVGF excitation energy (6.36 eV) is close to the MRDCI value (6.21 eV) and experimental data (6.2 eV). 

Table 4.7. Excitation energies (in eV) for transitions into the lowest excited states in the X2SiOz cluster (X = OSiH3) calculated at the optimized geometry of the 3 A electronic state using TD-B3LYP, EOM-CCSD, and CASPT2 methods...

Figure 4.13 n —it vertical excitation energy in formamide-water clusters with various low level methods (XX) in ONIOM(TD-B3LYP/6-311 +C(d,p) XX). L, M, and S stand for the large (6-311+C(d,p)), medium (6-31C(d)), and small (3-21G) basis sets, respectively. 

Protein QM region Environment SAC-CI Exptl. MRPT2 SORCI TD-B3LYP... 

Table 14-2. Computed barrier height (kcal/mol) for guanine and hypoxanthine corresponding to the keto-enol tautomerism in the ground and the lowest singlet tt-jt excited state obtained at the B3LYP/6-311++G(d,p) and TD-B3LYP/6-311++G(d,p)//CIS/X levels, respectively in the gas phase and in aqueous solution [163, 165]a...

Figure 20-4. TD-B3LYP/6-3 lG(d) computed transition energies of selected transitions of dG +pdG cation radical. Excitation energies are given in eV. (Reprinted with permission from ref. [153], J. Phys. Chem. (2006) American Chemical Society.)...

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