Modeling and analysing materials with theoretical tools is of great use when finding new systems for applications, for example, semiconductors with point defects can be used for quantum applications, like single photon emitters. One important aspect to consider symmetry, which can yield useful information about the properties of a system. To perform symmetry analysis, a code was developed that takes the orbitals of atomic structures, as calculated with Density Functional Theory simulations, as input. Specifically, the orbitals of molecules, and defects in solids are in focus. The symmetry analysis code calculates overlap of orbitals and their symmetry transformed counterpart, maps these overlaps to characters, finds the irreducible representations, and also finds which optical transitions are allowed. The code was tested on CH4 and SF6 molecules, and the divacancy defect in 4H-SiC. The symmetry analysis is performed easily and produces results that coincide well with other theoretical results. Furthermore, symmetry matrices can be approximated to be integer matrices, and the wave functions can be approximated with less accurate plane wave expansions by reducing the cutoff energy, and thus reducing the number of plane waves. These approximations shorten the calculation time and do not compromise the accuracy of the overlap. The code automates the symmetry analysis and is intended to be used in a high-throughput manner. / <p>2021-10-12 </p><p>The student thesis was first published online. </p><p>2022-02-25 </p><p>The student thesis was updated with an errata list which is downloadable from the permanent link.</p>
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:liu-180194 |
| Date | January 2022 |
| Creators | Stenlund, William |
| Publisher | Linköpings universitet, Teoretisk Fysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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