title: First-principles photoemission spectroscopy and orbital tomography in molecules from koopmans-compliant functionals.
abstract: The determination of spectral properties from first principles can provide powerful connections between microscopic theoretical predictions and experimental data, but requires complex electronic-structure formulations that fall outside the domain of applicability of common approaches, such as density-functional theory. We show here that Koopmans-compliant functionals, constructed to enforce piecewise linearity and the correct discontinuity derivative in energy functionals with respect to fractional occupation-i.e., with respect to charged excitations-provide molecular photoemission spectra and momentum maps of Dyson orbitals that are in excellent agreement with experimental ultraviolet photoemission spectroscopy and orbital tomography data. These results highlight the role of Koopmans-compliant functionals as accurate and inexpensive quasiparticle approximations to the spectral potential.
authors.affiliation: Theory and Simulations of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Ngoc Linh
authors.initials: NL
authors.lastname: Nguyen
authors.affiliation: Theory and Simulations of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Borghi
authors.affiliation: Centro S3, CNR-Istituto Nanoscienze, 41125 Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ferretti
authors.affiliation: Department of Materials Science and Engineering, Materials Research Institute, and Penn State Institutes of Energy and the Environment, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Ismaila
authors.initials: I
authors.lastname: Dabo
authors.affiliation: Theory and Simulations of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Nicola
authors.initials: N
authors.lastname: Marzari