Enhancing accuracy in predicting optical properties of explicitly solvated systems: a comprehensive approach through long-range separated tuning of RSH functional and sequential QM/MM

• Ano de defesa: 2023
• Autor(a) principal: Matias, Pedro Henrique Ferreira
• Orientador(a): Oliveira, Heibbe Cristhian Benedito de
• Banca de defesa: Oliveira, Heibbe Cristhian Benedito de, Ramalho, Teodorico de Castro, Colmati Junior, Flavio
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Química (IQ)
• Departamento: Instituto de Química - IQ (RMG)
• País: Brasil
• Palavras-chave em Português: Otimização de funcional; DFT; JGAP; Propriedades fotofísicas; s-QM/MM
• Palavras-chave em Inglês: Functional optimization; Photophysical properties
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA::ANALISE DE TRACOS E QUIMICA AMBIENTAL
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/13024

The properties of molecular systems are generally measured experimentally in solution. In a theoretical context, molecular modeling is done in vacuum, leading to discrepancies when comparing theoretical results with the experimental ones. In light of this, the use of solvation methods become necessary. However, existing methodologies do not allow optimizing the separation parameter of electronic interactions in RSH functionals ω. An approach to combine functional optimization of the functionals with explicitly solvated organic systems, such as para-Nitroaniline and Phenol Blue, was developed by this work. The explicit solvation was performed using the S-QM/MM methodology with ASEC-FEG approximations. The optimization process was performed using the JGAP scheme with a Golden Ratio-based search algorithm to minimize the number of calculations. RSH functionals are noteworthy for improving the description of photoelectronic properties, hence we decided to study such properties. Firstly, electronic excitation and non-linear optical properties calculations were performed for para-nitroaniline to verify the change in photophysical properties with functional optimization. The properties were evaluated as well for Phenol Blue systems, which has well-elucidated optoelectronic properties, to validate the methodology. Finally, the results showed that the proposed methodology is successful in explicit solvation. Photophysical properties were improved by circa 20%, in high polar systems, for para-Nitroaniline and Phenol Blue. NLO Properties for Phenol Blue have an good agreement for first-hyperpolarizability in non-polar and protic-polar systems, and secondhyperpolarizability have the best results in protic-polar systems.