RT-TDDFT

Chen, H., McMahon, J. M., Ratner, M. A., and Schatz, G. C. (2010) Classical electrod5mamics coupled to quantum mechanics for calculation of molecular optical properties a RT-TDDFT/FDTD approach, /. Phys. Chem. C, 114,14384-14392. 

As implied by Equation (4.11) and Equation (4.12), the computational cost of LR-TDDFT grows rapidly with increasing system size, because the size of the response matrices is proportional to the product of the numbers of occupied and unoccupied molecular orbitals, that is, (Voce x Aunocc- Moreover, the diffuse unoccupied orbitals usually require very large basis sets to satisfactorily converge the results. To circumvent these numerical challenges, a RT-TDDFT method was derived to track the response of an optical system upon external perturbation. In RT-TDDFT, an additional term, E r) x ]i r), is added to the system s quantum Hamiltonian, Hq, to reflect Kght-matter interactions ... 

Then, the scattered field, Esca r, t) and the incident field, Ei c r, t), are allowed to interact with the dye molecule in the time domain in a RT-TDDFT calculation. This is done using a two-dimensional Fourier transform via Xy(r,(d) ... 

Figure 2 Visible absorption spectra (n n state, onset at 550 nm) of tetrazine under different conditions (from top to bottom) (a) aqueous solution at room temperature (RT), (b) cyclohexane at RT, (c), hydrocarbon matrix at 77 K, (d) gas phase at RT, and (e) TDDFT-BdLYP simulation of the vibronic transitions at RT. The 0-0 vibronic transition has been set to zero.

---