AUTHOR=Buelna-García Carlos Emiliano , Castillo-Quevedo Cesar , Quiroz-Castillo Jesus Manuel , Paredes-Sotelo Edgar , Cortez-Valadez Manuel , Martin-del-Campo-Solis Martha Fabiola , López-Luke Tzarara , Utrilla-Vázquez Marycarmen , Mendoza-Wilson Ana Maria , Rodríguez-Kessler Peter L. , Vazquez-Espinal Alejandro , Pan Sudip , de Leon-Flores Aned , Mis-May Jhonny Robert , Rodríguez-Domínguez Adán R. , Martínez-Guajardo Gerardo , Cabellos Jose Luis 

TITLE=Relative Populations and IR Spectra of Cu38 Cluster at Finite Temperature Based on DFT and Statistical Thermodynamics Calculations

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.841964

DOI=10.3389/fchem.2022.841964

ISSN=2296-2646

ABSTRACT=<p>The relative populations of Cu<sub>38</sub> isomers depend to a great extent on the temperature. Density functional theory and nanothermodynamics can be combined to compute the geometrical optimization of isomers and their spectroscopic properties in an approximate manner. In this article, we investigate entropy-driven isomer distributions of Cu<sub>38</sub> clusters and the effect of temperature on their IR spectra. An extensive, systematic global search is performed on the potential and free energy surfaces of Cu<sub>38</sub> using a two-stage strategy to identify the lowest-energy structure and its low-energy neighbors. The effects of temperature on the populations and IR spectra are considered via Boltzmann factors. The computed IR spectrum of each isomer is multiplied by its corresponding Boltzmann weight at finite temperature. Then, they are summed together to produce a final temperature-dependent, Boltzmann-weighted spectrum. Our results show that the disordered structure dominates at high temperatures and the overall Boltzmann-weighted spectrum is composed of a mixture of spectra from several individual isomers.</p>