This database constains all computations reported in the paper, organized in the following folders: Benchmark This folder contains the computations of the BDT-TDO and Phen-DPP trimers reported in Sections S1-S4 of ESI Each contain 3 folders corresponding to RAS-2SF (done with Qchem), RASPT2 (done with OpenMolcas) and SF-TDDFT (done with Qchem) computations BDT-TDO Extended benchmark is performed for BDT-TDO, for which basis-set and functional testing is done RAS-2SF 5 basis set were tested for BDT-TDO SF-TDDFT 6 basis set and 16 functionals were tested SF-TDDFT is performed with triplet unrestricted DFT (uDFT) reference giving access to singlet and triplet states (singlet-triplet folder) and with quintuplet uDFT as reference giving access to triplet and quituplet states (triplet-quintuplet folder) RASPT2 Computations for singlet, triplet and quintuplet states is done, with RASSCF(22,2,2;9,4,7) active space Phen-DPP In this case, only one set of computations is done for each method RAS-2SF 6-31g(d) basis set is used SF-TDDFT wb97X-D and 6-31g(d) basis set is used RASPT2 The active space in this case is RASSCF(30,2,2;13,4,9) The 2A-model, 4A-model and 5A-model folders contain the DFT geometry optmizations (done with Gaussian) and RAS-2SF (labelled RASCI) computations (performed with Qchem) for the truncated A-D-A (2A), A-D-A-D-A-D-A (4A), A-D-A-D-A-D-A-D-A (5A) models, of the 9 compounds: 1-BDT-TDO 2-BDTMe-TDO 3-TT-TDO 4-BDT-DPP 5-BDTSo2-DPP 6-BDTSo2-DPPMe 7-Phen-DPP 8-Naph-DPP 9-TT-DPP For the 2A-model and 4A-model, the GS singlet, the T1 minimum, the TT (quintuplet) and the intermediate (ts) geometries were optimized Note that the ts geometry can be either a transition state or a minimum as explained in the main text For the TT geometry, RASCI is performed For the 5A-model, the TT (quintuplet) geometry and the 2T1 (quintuplet) geometry corresponding to the A-D-T-D-T-D-A-D-A and A-D-T-D-A-D-T-D-A sequences, respectively, were computed. For both geometries, RASCI was performed. Additional computations that can be found are: For BDT-TDO and BDT-DPP Optimization of the T1 and ts geometries RASCI performed for the ts geometries For BDT-TDO Evaluation of the spin density with PBE0 and wb97X-D functionals on the TT, 2T1 and ts geometries