Confissões e falsas confissões: A perspectiva do investigador

Dissertação de Mestrado apresentada ao Instituto Superior de Psicologia Aplicada para obtenção de grau de Mestre na especialidade de Psicologia Clínica.

Samuel Chamberlain: un granuja norteamericano durante “la hora más triste de nuestra historia”

Samuel Chamberlain (1829-1908) fue un soldado estadounidense que participó en la guerra de intervención norteamericana en México. Su nombre, como el de tantos otros miles de hombres que combatieron en esta tristemente recordada conflagración, pudo olvidarse, pero no fue así por dos motivos: escribir sus memorias a las que tituló My confession: the recollections of a rogué –título que podría traducirse como Mi confesión: recuerdos de un granuja– y por plasmar en pinturas algunas de sus vivencias ocurridas durante el transcurso de este conflicto.

Amor e criação: A universalidade das cartas portuguesas

Dissertação de Mestrado apresentada no ISPA – Instituto Universitário para obtenção do grau de Mestre em Psicologia especialidade de Psicologia Clínica.

Excitonic properties of transition metal oxide perovskites and workflow automatization of GW schemes

The Many-Body-Perturbation Theory approach is among the most successful theoretical frameworks for the study of excited state properties. It allows to describe the excitonic interactions, which play a fundamental role in the optical response of insulators and semiconductors. The first part of the thesis focuses on the study of the quasiparticle, optical and excitonic properties of \textit{bulk} Transition Metal Oxide (TMO) perovskites using a G$_0$W$_0$+Bethe Salpeter Equation (BSE) approach. A representative set of 14 compounds has been selected, including 3d, 4d and 5d perovskites. An approximation of the BSE scheme, based on an analytic diagonal expression for the inverse dielectric function, is used to compute the exciton binding energies and is carefully bench-marked against the standard BSE results. In 2019 an important breakthrough has been achieved with the synthesis of ultrathin SrTiO3 films down to the monolayer limit. This allows us to explore how the quasiparticle and optical properties of SrTiO3 evolve from the bulk to the two-dimensional limit. The electronic structure is computed with G0W0 approach: we prove that the inclusion of the off-diagonal self-energy terms is required to avoid non-physical band dispersions. The excitonic properties are investigated beyond the optical limit at finite momenta. Lastly a study of the under pressure optical response of the topological nodal line semimetal ZrSiS is presented, in conjunction with the experimental results from the group of Prof. Dr. Kuntscher of the Augsburg University. The second part of the thesis discusses the implementation of a workflow to automate G$_0$W$_0$ and BSE calculations with the VASP software. The workflow adopts a convergence scheme based on an explicit basis-extrapolation approach [J. Klimeš \textit{et al.}, Phys. Rev.B 90, 075125 (2014)] which allows to reduce the number of intermediate calculations required to reach convergence and to explicit estimate the error associated to the basis-set truncation.