Those benchmarks can be expensive, however. In the present example, the cost of LR-TDDFT remains considerably lower than that of TDKS even though several hundred individual excited states are required just to obtain the near-edge Ti(2p) features. For the Ti(2p) CVS active space, a calculation with o = 3 active orbitals and v = 128 virtual orbitals (which is the entire virtual space in the def2-TZVPD basis set) requires less than 3 min on 20 processors. LR-TDDFT calculations with a O(1s) active space required about 2 min. TDKS simulations, running on the same hardware, require 14.3 hours to reach t max = 1200 a.u.. Assuming that the near-edge features could be obtained using t max = 75 a.u., as for the [C 4 C 1 Im][SCN] system considered above, then a more pragmatic calculation would require almost an hour an 20 processors. This does not include the time required for convergence testing.