RT-SIESTA is a real-time time-dependent density functional theory code for the computation of linear and non-linear optical response.

The code is an extension of the SIESTA code, and takes advantage of its efficient linear combination of atomic orbitals (LCAO) basis set, and use of pseudopotentials. Together with the PCCN (predictor-corrector Crank-Nicolson algorithm) approach, these allow for routine simulation of systems with up to 300 atoms.

The Onsager continuum solvation model has also been implemented in RT-SIESTA.

Further information about this code can be found here (http://monalisa.phys.washington.edu/feffproject-rtsiesta.html).