title: Open-ended response theory with polarizable embedding: multiphoton absorption in biomolecular systems.
abstract: We present the theory and implementation of an open-ended framework for electric response properties at the level of Hartree-Fock and Kohn-Sham density functional theory that includes effects from the molecular environment modeled by the polarizable embedding (PE) model. With this new state-of-the-art multiscale functionality, electric response properties to any order can be calculated for molecules embedded in polarizable atomistic molecular environments ranging from solvents to complex heterogeneous macromolecules such as proteins. In addition, environmental effects on multiphoton absorption (MPA) properties can be studied by evaluating single residues of the response functions. The PE approach includes mutual polarization effects between the quantum and classical parts of the system through induced dipoles that are determined self-consistently with respect to the electronic density. The applicability of our approach is demonstrated by calculating MPA strengths up to four-photon absorption for the green fluorescent protein. We show how the size of the quantum region, as well as the treatment of the border between the quantum and classical regions, is crucial in order to obtain reliable MPA predictions.
authors.affiliation: Centre of Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø-The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: Arnfinn Hykkerud
authors.initials: AH
authors.lastname: Steindal
authors.affiliation: Centre of Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø-The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: Maarten T P
authors.identifier: http://orcid.org/0000-0003-3976-9223
authors.initials: MT
authors.lastname: Beerepoot
authors.affiliation: Centre of Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø-The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: Magnus
authors.initials: M
authors.lastname: Ringholm
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense, Denmark. jmo@sdu.dk.
authors.forename: Nanna Holmgaard
authors.initials: NH
authors.lastname: List
authors.affiliation: Centre of Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø-The Arctic University of Norway, N-9037 Tromsø, Norway.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Ruud
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense, Denmark. jmo@sdu.dk.
authors.forename: Jacob
authors.initials: J
authors.lastname: Kongsted
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense, Denmark. jmo@sdu.dk and Laboratory of Computational Chemistry and Biochemistry, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Jógvan Magnus Haugaard
authors.identifier: http://orcid.org/0000-0001-7487-944X
authors.initials: JM
authors.lastname: Olsen
mesh_terms: D049452:Green Fluorescent Proteins / Q000737:chemistry*; D008956:Models, Chemical; D017785:Photons; D055585:Physical Phenomena; D012997:Solvents / Q000737:chemistry
chemical_list: D012997:Solvents; D049452:Green Fluorescent Proteins