<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes"^^ . "During the last three decades, the field of theoretical and computational chemistry has\r\nevolved rapidly, promoted by the increasing availability of computational power inherent in\r\nmodern CPUs and cluster structures. This development has expressed itself in a particular\r\nmanner in the formulation of modern state-of-the-art electronic structure methods in the\r\nframeworks of, for instance, the Algebraic Diagrammatic Construction scheme or Coupled\r\nCluster. Application of these methods to the calculation of molecular excitation energies\r\nand properties that describe the most fundamental processes of light-matter interaction, has\r\nbeen established as a profound and reliable tool for experimentalists within chemistry and\r\nmolecular sciences.\r\nThis work, which is spilt into three main parts, presents the implementation as well as\r\nbenchmarking of novel electronic structure methods for the Algebraic Diagrammatic\r\nConstruction scheme (ADC) as well as Unitary Coupled Cluster (UCC).\r\nIn the first part, an implementation and benchmark study for the calculation doubly-ionized\r\nas well as double electronically-attached states for ADC, termed DIP-ADC and DEA-ADC,\r\nrespectively, up to third order is presented. The implementation was executed in the\r\nQ-Chem program package, benchmark studies included the comparison of states to Full CI\r\ndata for DIP as well as EOMDIP-CCSD and EOMDEA-CCSD. For both schemes, the\r\nthird-order methods DIP-ADC(3) as well as DEA-ADC(3) proved to produce results which\r\nare in a remarkable good agreement to the corresponding EOM-CCSD method.\r\nAs for the second part, a benchmark study on core excitation energies in the framework of\r\nUnitary Coupled Cluster was presented. To this end, the Core-valence separation\r\napproximation was applied to the second-and third-order UCC schemes for electron\r\nexcitations. It was shown that CVS-UCC is very suitable in the computation of X-ray\r\nspectra, similar to CVS-ADC, which has been studied before by Wenzel et al. and that it\r\nprovides reliable data for the description and simulation of energetically high-lying core\r\nexcitations.\r\nThe last part of this work features an implementation of an automated code generator for\r\nUnitary Coupled Cluster as it was realized by Leitner et al. for the computation of\r\nelectronically excited states on a ADC(4) level. Working equations for a UCC3-x scheme\r\n(in similarity to UCC2-x with an extended description of the doubles/doubles block of the\r\nsecular matrix) as well as a full UCC4 for the calculation of electronically-excited states\r\nand properties are presented, together with an improved ground-state description, termed\r\nUCC4+5[s,t] that includes fifth-order terms.\r\nAt the end of this work, all results for the three presented topics are summarized in detail,\r\naccompanied by a short outlook of what could include future work and development."^^ . "2023" . . . . . . . "Sebastian Markus"^^ . "Thielen"^^ . "Sebastian Markus Thielen"^^ . . . . . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes (PDF)"^^ . . . "phd_smthielen.pdf"^^ . . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Development and Benchmarking of\r\nNovel Electronic Structure Methods based on\r\nthe Algebraic Diagrammatic Construction and\r\nUnitary Coupled Cluster Schemes (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #34273 \n\nDevelopment and Benchmarking of \nNovel Electronic Structure Methods based on \nthe Algebraic Diagrammatic Construction and \nUnitary Coupled Cluster Schemes\n\n" . "text/html" . . . "530 Physik"@de . "530 Physics"@en . . . "540 Chemie"@de . "540 Chemistry and allied sciences"@en . .