Descripción del proyecto
Átomos pesados: llegar al núcleo del problema químico cuántico
Las descripciones de las estructuras, las fuerzas y los comportamientos nucleares y moleculares se basan en la química cuántica. En el caso de átomos ligeros con menos electrones, estas descripciones son muy precisas. Sin embargo, los átomos pesados tienen muchos electrones, lo que da lugar a estructuras electrónicas más grandes y complejas con electrones con una velocidad relativamente alta, lo que dificulta estas descripciones. La aplicación de la electrodinámica cuántica (EDC o QED, por sus siglas en inglés) ha mejorado un poco la precisión, pero hasta ahora se ha limitado a los electrones de valencia. Hoy día no existen herramientas fiables para estudiar la región del núcleo donde se generan los efectos de la EDC. En el proyecto HAMP-vQED, financiado con fondos europeos, se está desarrollando un marco informático para ejecutar cálculos de alta precisión a fin de abordar esta limitación, lo que tendrá repercusiones para el modelo estándar y otras teorías cuánticas de campos.
Objetivo
Quantum chemical calculations are today in a position where they not only assist, but may also challenge experiment, at least for molecules containing light atoms only. When heavy atoms are present, achieving the same accuracy becomes more challenging, not only because of relativistic effects, but also because the larger number of electrons and the often complicated electronic structures make the electron correlation problem harder. When surveying the physics that has to be included in order to establish a reliable computational protocol for heavy-element chemistry, the role of quantum electrodynamics (QED) should at least be considered. Studies so far indicate that QED-effects reduce relativistic effects by about 1%. However, such investigations have been mostly limited to valence properties, since there are currently no reliable tools for general molecules to study the core region where the QED-effects are generated. The HAMP-vQED project aims to fill this gap by providing a computational machinery allowing highly accurate calculations of molecular properties, with particular focus on properties that probe electron density in the core region, such as NMR parameters. I insist on a variational approach to QED using the local, finite basis sets of quantum chemistry. In short, I want to do QED without diagrams. This allows me to verify the domain of validity of currently used effective QED-potentials and provide a more consistent formulation of relativistic quantum mechanics. QED has been called the last train from physics to chemistry. The HAMP-vQED project provides a train back to physics in the form of highly accurate calculations which, combined with experiment, will allow the exploration of nuclear structure, the standard model of the universe and beyond. An even more tantalizing perspective is that such a variational scheme to QED may inspire progress in other quantum field theories, such as quantum chromodynamics, where perturbation theory is more problematic.
Ámbito científico
- natural sciencesphysical sciencestheoretical physicsparticle physics
- natural scienceschemical sciencesphysical chemistryquantum chemistry
- natural sciencesphysical sciencesquantum physicsquantum field theory
- natural sciencescomputer and information sciencescomputational science
- natural sciencesmathematicsapplied mathematics
Programa(s)
Régimen de financiación
ERC-ADG - Advanced GrantInstitución de acogida
75794 Paris
Francia