QUANTUM THEORY

Author: VENDRELL ROMAGOSA ORIOL.
Year: 2004.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: FACULTAT DE CIÈNCIES.
Place of preparation: ESCUELA DE POSTGRADO.

Summary: The dissertation is based on a study from a molecular dynamics protónica transfer processes, mainly in electronic excited states. The introduction covers the basics of the techniques more common today, quantum dynamics, methods cuánticos-clásicos and classical methods. One learns processes and tunnel link with the rotation of the methyl group in the molecule 5-metiltropolona. It also explores the process of transferring protónica and its relationship to the environment supra, with the overall impact of the environment and the specific effects of an environment prótico. Another treaty system is the transfer multiple protónica through a chain of water molecules, for which there is a small-scale model in which investigations are carried out by quantum dynamics. It establishes a strong correlation between degrees of freedom lighter and pesantes, and non-severability of the nuclear wave function. The thesis also provides a dynamic study on the elimination of hydrogen in metal ruthenium complexes, based on a two-dimensional model and a spread of the nuclear wave function using Fourier transform.

Author: GONZÁLEZ AGUILAR JAVIER JOSÉ.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: UNIVERSIDAD DE BARCELONA.

Summary: The thesis is divided into three parts. In the first part, starting from the definition of road reaction develops the theory of hamiltonianao the path of reaction, generalizándolo for any way that complies with the requirements found. The findings apply to the Coordinated Reaction Intrinsic, the Way Reaction Newton and Tracking Reduced Gradient. Likewise, the results obtained with the first two reaction paths are applied to the study of various reactions; isomerization of hydrogen cyanide, the migration of one of the hidrógenos oxide etino and overture conrotatória of ciclobuteno. The second part used the results of the first to estimate how varies the density of states in the phase space through the Liouville equation. It developed two different methods for solving the equation planted and discussed the initial conditions to be used. Finally, the results are applied to the calculation of average reaction rate constant, calculation is done in the case of surface MÃ ¼ ller-Brown. Also stresses the inequality found, which shows the method developed as a result of lower than in the theory of state of transition to a time that is still higher than the actual result. Finally, the third part begins with a discussion of the mechanics bohmiana; their bases and some details of particular relevance. It develops a new expression to calculate the evolution of wave functions, according to the discrete variable representation and explores some cases simple. Once the above, given the quantum formulation of hamiltoniano the path of reaction, considering several cases simple thesis and finally ends with the phrase as quantum mechanics bohmiana calculation of constant reaction rate.

Author: RICO ORTEGA ENRIQUE.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: UNIVERSIDAD DE BARCELONA.

Summary: In the thesis develop ideas and concepts that involve three major areas such as physics, quantum field theory, quantum information and condensed matter. In the first chapter describes systems with one-dimensional quantum information tools. A second chapter is related concepts such as interlocking and group renormalización. A third chapter describes how to perform, group renormalización on states.

Author: FERNÁNDEZ GALVÁN IGNACIO.
Year: 2004.
University: EXTREMADURA [www.unex.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS, UNIVERSIDAD DE EXTREMADURA.

Summary: In recent decades, computational chemistry has become a very important tool for the study of the properties of matter. The condensed-phase systems especially in liquid phase-presented, however, a number of properties that make it necessary ele development of specific methods and the introduction of additional approaches to the normally used for systems in gas phase. This thesis focuses on one of these methods, called ASEP / MD (Averaged Solvent Electrostatic Potential from Molecular Dynamics) and developed by our research group. The method ASEP / MD has been expanded to allow for the optimization of molecular structures in solution, which is required delas derived from the free energy with respect to nuclear coordinates. As complementary work, it has developed a method for calculating free energy differences and verify quantitatively the validity of the approximation of the field means, used by our method. It has also developed a computer program that facilitates the implementation of development theory. There have also been some practical applications to systems of interest. The validity of the approximation half of the field has been verified with simple systems as alcohols in liquid and aqueous solutions of compounds carboncillos. The proper functioning of geometry optimization method has been verified with simple molecules such as water, methanol or formamide. It has carried out a more detailed study on the balance anomérico a monosaccharide, D-xilopiranosa, and a reaction SN2, the reaction of Menshutkin between NH3 and CH3Cl. Finally, we have studied the dynamics of the isomerization of triazeno (N3H3) in water through a combined application of the method ASEP / MD and a method QM / MM traditional.

Author: RODRIGUEZ BALADA ELENA.
Year: 2005.
University: ROVIRA I VIRGILI [www.urv.cat].
Place of defense: FACULTAT DE QUIMICA.
Place of preparation: FACULTAT DE QUIMICA DE LA URV.

Author: RUIZ DELGADO MARÍA DEL CARMEN.
Year: 2005.
University: MÁLAGA [www.uma.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS, UNIVERSIDAD DE MÁLAGA.

Summary: The main objective of this research is to rationalize the properties structural, electronic and optical several families oligotiofenos precursors systems organic electroactivos with high technological potential. This has been used spectroscopic methods (UV-VIS-NIR, IR and Raman) and calculations químico-cuánticos. Occasionally has also made use of electrochemical techniques (cyclic voltammetry), espectroquímicas and espectroelectroquímicas spot (UV-VIS-NIR, IR and Raman) to discuss species loaded. All systems studied in this paper, is derived systems oligotiofenos with different profile replacement symmetric (D *- Do A-*- A), asymmetric or "push-pull" (D *- A) or replacement alternating (DDA). The replacement scheme, which is responsible for the structural modifications, will ultimately determine the electronic and optical properties of the compounds, led to systems with good behavior redox anfotérico systems with high response ONL second order systems or "low gap mail, "respectively. In turn, these properties químico-físicas will provide different types of organic materials of potential applicability in OFETs, devices ONL or solar cells, among others.

Author: LUIS PASTOR ABIA.
Year: 2006.
University: ALICANTE [www.ua.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: UNIVERSIDAD DE ALICANTE.

Summary: The correct estimation of the energy correlation (defined as the difference in the exact power of a system that would be less of a Hartree - Fock calculation) is very important in the calculations mecano-cuánticos. The traditional way of including these effects is to increase the number of determinants of the wave function in a treatment post-HF. This vastly increases the computational cost under increasing the number of determinants. In comparison, the theory DFT provides an estimate of the energy correlation with a fairly small computational effort, but presents a number of problems for certain cases that require treatment multideterminantal. All this means that combining the calculation of a wave multideterminantal small and estimate the rest of the energy correlation through a functional correlation is an open field for huge interés.En this thesis has been made calculations multideterminantales, type GVB pp-and CASSCF, which have been added energy correlation using different functional energy correlation. Although in principle the inclusion of the correlation should be made on the process autoconsistencia (CWS) has found that, as with the functions monodeterminantales their inclusion in a step post (post-SCF) is from the point for quite precise and energy-saving both time and complexity of calculation. This methodology has been applied to excited states where the theory DFT presents some difficulties. The results of this application are encouraging for some kind of functional but appear certain problems with the dual account of the energy correlation: the functional employees, despite being sensitive to the quality of the wave function, are unable to take account of a precise fraction of the energy correlation already included in the calculation multideterminantal, which indicate different lines to be followed to achieve this.