International Journal for Innovation Education and Research www.ijier.net Vol:-9 No-01, 2020 International Educative Research Foundation and Publisher © 2021 pg. 485 Pereskia aculeata vibrational model by Raman characterization and DFT method Quesle da Silva Martins Departamento de Física, Universidade Federal de Rondônia, Ji-Paraná, R. Rio Amazonas, 351 - Jardim dos Migrantes, Ji-Paraná - RO, 76900-726. ORCID: https://orcid.org/0000-0002-1315-2164 Email: quesle@fisica.ufmt.br Natali Felix Arinos Instituto de Física, Universidade Federal de Mato Grosso, Cuiabá, Av. Fernando Correa da Costa, 2.367 – Boa Esperança, 78060-900, Mato Grosso. ORCID: https://orcid.org/0000-0003-4732-7759 Email: talifelix@fisica.ufmt.br Cristian Aguirre Tellez Instituto de Física, Universidade Federal de Mato Grosso, Cuiabá, Av. Fernando Correa da Costa, 2.367 – Boa Esperança, 78060-900, Mato Grosso. ORCID: https://orcid.org/0000-0001-8064-6351 Email: cristian@fisica.ufmt.br Jorge Luiz Brito de Faria Instituto de Física, Universidade Federal de Mato Grosso, Cuiabá, Av. Fernando Correa da Costa, 2.367 – Boa Esperança, 78060-900, Mato Grosso. ORCID: https://orcid.org/0000-0002-7066-6823 Email: hulk@fisica.ufmt.br Abstract Raman scattering was used to obtain vibrational modes in a Pereskia aculeata sample. The obtained spectrum was compared with quercetin's theoretical spectra, kaempferol, isorhamnetin, rutinose, caffeic, and tartaric acid, generated from the density functional theory (DFT) method, which used structures of the known composition present in the sample. Among the main compounds, phenolic acids and flavonoids are mentioned. Vibrational signatures, designated as CO and CH group modes, are abundant and bands in the region between 800 and 1800 cm -1 . This showed that the theoretical and experimental results had good correspondence between the flavonoids. Statistical observations of correlation and principal component analysis (PCA) were used, which helped in the process of correlation between sample and data obtained. Theoretical spectra have been corrected by a single scale factor of 0.961, and vibrational contributions by the molecular group were via VEDA software. Keywords: Raman spectrum; DFT method; Ora-Pro-Nóbis; phenolic; flavonoids; 1. Introduction The United Nations (UN) presented data on population projections, and contrary to what was previously