Spectroscopic analysis of atoms and molecules

Doctorate in Physics of Nanostructures and Advanced Materials by Alison Crawford Uranga.I would like to thank the Donostia International Physics Centre and the Departamento de Educación, Universidades e Investigación del Gobierno Vasco (Ref. BFI-2011-26) for the financial support to carry out this thesis.Peer Reviewe

Quantum-ionic features in the absorption spectra of homonuclear diatomic molecules

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).We show that additional features can emerge in the linear absorption spectra of homonuclear diatomic molecules when the ions are described quantum mechanically. In particular, the widths and energies of the peaks in the optical spectra change with the initial configuration, mass, and charge of the molecule. We introduce a model that can describe these features and we provide a quantitative analysis of the resulting peak energy shifts and width broadenings as a function of the mass.We acknowledge financial support from the European Research Council Advanced Grant DYNamo (Grant No. ERC-2010-AdG-267374), Spanish Grants No. FIS2013-46159-C3-1-P and No. PIB2010US-00652, and Grupo Consolidado UPV/EHU del Gobierno Vasco (Grant No. IT578-13). A.C.-U. acknowledges financial support from the Departamento de Educacion, Universidades e Investigacion del Gobierno Vasco (Reference No. BFI-2011-26).Peer Reviewe

Non-adiabatic transition in the optical spectra of simple molecular systems

Trabajo presentado al 9th ETSF Young Researchers' Meeting celebrado en Bruselas (Bélgica) del 21 al 25 de Mayo de 2012.Peer reviewe

Efficient and accurate modeling of electron photoemission in nanostructures with TDDFT

We derive and extend the time-dependent surface-flux method introduced in [L. Tao, A. Scrinzi, New J. Phys. 14, 013021 (2012)] within a time-dependent density-functional theory (TDDFT) formalism and use it to calculate photoelectron spectra and angular distributions of atoms and molecules when excited by laser pulses. We present other, existing computational TDDFT methods that are suitable for the calculation of electron emission in compact spatial regions, and compare their results. We illustrate the performance of the new method by simulating strong-field ionization of C60 fullerene and discuss final state effects in the orbital reconstruction of planar organic molecules

Non-adiabatic effects in the 1D optical spectra oh H2+ and H2

Trabajo presentado a la 3rd edition of the International Conference on Advanced Materials Modelling, celebrada en Nantes (Francia) del 7 al 9 de Julio de 2014.Peer reviewe

Ionisation of atoms within TDDFT / Nuclear effects on the TRPES

Trabajo presentado al 2nd International Science at FELs Conference, celebrado en Villigen (Suiza) del 15 al 17 de Septiembre de 2014.Peer reviewe

Finite-mass effects beyond the Born-Oppenheimer approximation in the spectroscopy of three-body systems

Trabajo presentado al: "Deutsche Physikalische Gesellschaft Spring Meeting" celebrado en Regensburg (Alemania) del 10 al 15 de Marzo de 2013.In this work we utilize a Lagrange-Laguerre variational method to construct highly accurate numerical solutions for non-relativistic three-body systems (Helium atom, H+2, HD+ and dtμ in 3D). Our approach does not rely on the Born-Oppenheimer approximation. This allows us to investigate the mass-dependence of optical dipole absorption spectra. For the molecular systems H+2, HD+ and dtμ, we find a rather pronounced mass dependence of the dipole transiton matrix elements close to the second ionization threshold. We compare our 3D results to one-dimensional model calculations and provide a mechanism in terms of non-adiabatic coupling elements.Peer reviewe