Accurate Theoretical Description of the L-1(a) and L-1(b) Excited States in Acenes Using the All Order Constricted Variational Density Functional Theory Method and the Local Density Approximation

作者：Krykunov Mykhaylo^*; Grimme Stefan; Ziegler Tom

来源：Journal of Chemical Theory and Computation, 2012, 8(11): 4434-4440.

DOI：10.1021/ct300372x

We present the results of calculations on the vertical singlet L-1(a) and L-1(b) excitation energies in acenes within time dependent density functional theory (TDDFT), second order constricted variational DFT (CV(2)-DFT), and all order constricted variational DFT (CV(infinity)-DFT) using the local density approximation LDA(VWN). For the linear acenes it is shown that the application of the Tamm-Dancoff (TD) approximation to TDDFT (TDDFT-TD) substantially improves the agreement with experiment compared to pure TDDFT. This improvement leads to the correct ordering of the L-1(a) and L-1(b) excitation energies in naphthalene. As TDDFT-TD is equivalent to the second order CV(2)-TD method one might hope for further improvements by going to all orders in CV(infinity)-TD. Indeed, for linear acenes the application of the CV(infinity)-TD method brings the agreement with experiment to within 0.1 eV for both types of excitations using the simple LDA functional. The CV(infinity)-TD method based on LDA is also shown to be accurate for 15 nonlinear acenes with root-mean-square deviations of 0.24 eV for L-1(a) and 0.17 eV for L-1(b).

• 出版日期2012-11