title: Many-Body Perturbation Theory Extended to the Quantum Mechanics/Molecular Mechanics Approach: Application to Indole in Water Solution.
abstract: Optical properties of aromatic chromophores are used to probe complex biological processes, yet how the environment tunes their optical properties is far from being fully understood. Here we present a method to calculate such properties on large-scale systems, like biologically relevant molecules in aqueous solution. Our approach is based on many-body perturbation theory combined with a quantum mechanics/molecular mechanics (QM/MM) approach. We include quasiparticle and excitonic effects for the calculation of optical absorption spectra in a QM/MM scheme. We apply this scheme, together with the well-established TDDFT approach, to indole in water solution. Our calculations show that the solvent induces a red shift in the main spectral peak of indole, in quantitative agreement with the experiments, and they point to the relevance of both the electrostatic and geometrical origin of the shift.
authors.affiliation: NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita' di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2-4, Trieste, Italy.
authors.forename: Adriano Mosca
authors.initials: AM
authors.lastname: Conte
authors.affiliation: NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita' di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2-4, Trieste, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Ippoliti
authors.affiliation: NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita' di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2-4, Trieste, Italy.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Del Sole
authors.affiliation: NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita' di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2-4, Trieste, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Carloni
authors.affiliation: NAST, ETSF, CNR INFM-SMC, Department of Physics, Universita' di Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma, Italy, Democritos, SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Beirut 2-4, I-34014 Trieste, Italy, and Italian Institute of Technology, SISSA Unit, Via Beirut 2-4, Trieste, Italy.
authors.forename: Olivia
authors.initials: O
authors.lastname: Pulci