 Development of explicitly correlated local correlation methods THESIS TOPIC PROPOSAL Institute: Budapest University of Technology and Economics chemistry George A. Olah Doctoral School of Chemistry and Chemical Technology Thesis supervisor: Mihály Kállay Location of studies (in Hungarian): BME Department of Physical Chemistry and Materials Science Abbreviation of location of studies: BME Description of the research topic: The local correlation methods developed in our group allow for the accurate calculation of molecular energies, and thus the estimation of energy differences relevant for chemistry, such as reaction heats, complexation energies, or barrier heights. However, these calculations are still rather time-consuming as large one-electron basis sets are required due to the slow convergence of the correlation energy with the size of the basis set. The basis set convergence of correlation methods can be accelerated by explicitly correlated methods, which employ wave function models explicitly depending on the inter-electronic coordinates. In this project, first, reduced-cost canonical explicitly correlated Møller–Plesset (MP2) and coupled-cluster singles and doubles with perturbative triples [CCSD(T)] methods will be developed invoking the frozen natural orbital and natural auxiliary function approximations, which are also the cornerstones of our local correlation approaches. In the second step, based on the above developments, explicitly correlated local MP2 and CCSD(T) approaches will be designed and implemented. The new methods will be tested for the calculation of total energies, reaction energies, and interaction energies for large molecular systems. Number of students who can be accepted: 1 Deadline for application: 2024-05-30 |