Time-dependent density functional theory (TDDFT) is implemented within the Tamm-Dancoff approximation (TDA) using a pseudospectral approach to evaluate two-electron repulsion integrals. The pseudospectral approximation uses a split representation with both spectral basis functions and a physical space grid to achieve a reduction in the scaling behavior of electronic structure methods. We demonstrate here that exceptionally sparse grids may be used in the excitation energy calculation, following earlier work employing the pseudospectral approximation for determining correlation energies in wavefunction-based methods with similar conclusions. The pseudospectral TDA-TDDFT method is shown to be up to ten times faster than a conventional algorithm for hybrid functionals without sacrificing chemical accuracy.
REFERENCES
Selection of these grids for Coulomb/exchange evaluation within JAGUAR is performed by setting the keyword iopt287 to 1, 2, 12, or 9 for the c, m, C, and M grids, respectively. Similarly, the keyword iopt286 can be set to the same values to select the grid which is used for the quadrature of the exchange-correlation contribution.