• QM/MM simulation of excited state dynamics
• diamino-p-benzoquinone
• Singlet fission

The subject of this thesis is the computational study of 2,3-diamino-1,4-benzoquinone as a possible chromophore for singlet fission, a process in which a photogenerated singlet excited state is converted into two triplet excited states. The singlet fission could be exploited to increase the efficiency of photovoltaic devices, by generating two excited states with one photon. After a preliminary computational investigation on the isolated molecule and a possible dimeric structure, the QM/MM simulation of excited state dynamics for a dimer in a computed crystal structure is performed. Moreover, ab initio calculations are carried out to inspect the reliability of the computed excitation energies of 2,3-diamino-1,4-benzoquinone and two more chromophores reported in a previous work where these molecules were designed and proposed for singlet fission.