Banca de DEFESA: TATYARA MONTEIRO DA SILVA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : TATYARA MONTEIRO DA SILVA
DATE: 10/10/2023
TIME: 09:00
LOCAL: Remotamente: https://conferenciaweb.rnp.br/webconf/yuri-27
TITLE:
REMODELING THE POTENTIAL ENERGY SURFACE OF THE F + H2O → HF + OH CHEMICAL REACTION
PAGES: 63
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química Teórica
SUMMARY:
Potential energy surfaces (PES) are mathematical functions that describe the interaction between atoms during a chemical reaction. Knowing this, Computational Chemistry allows us to build SEPs of chemical reactions, which have various applications, such as the study of reaction dynamics and vibrational spectroscopy. The accuracy of the results will depend directly on the accuracy of the SEP itself, in particular the energies of the stationary states. In order to build a SEP, it is necessary to carry out various electronic structure calculations. However, as these calculations can be computationally expensive, the electronic energy of just a few points in the space of nuclear configurations can often be calculated using more accurate methods. For this reason, strategies have been developed to remodel SEPs already described in the literature, so that they describe the energies of stationary states calculated by electronic structur methods potentially more accurate.
We then propose a remodelling described by a mathematical expression that is obtained by multiplying the original SEP by a sum of Gaussians, each centered on a stationary point whose energy we wish to modify. The Gaussian, in this case, is the function that will be responsible for reshaping the SEP. By using this expression, we can see that the reshaping will not be adequate when the SEP has geometries with energy equal to zero, as this generates singularities in the function that does the reshaping. It is therefore possible to solve this problem by remodeling a SEP withshifted energies using a constant.
After defining the remodeling procedure, we applied it to the SEP of the chemical reaction F + H2O→HF + OH, which was developed by Professor Hua Guo's group. We were able to remodel this SEP, modifying relative energies of the stationary
points. In some regions of the SEPs (original and remodelled) the energies and behavior of both were similar, but with modifyied relative energies. This difference can affect the dynamics and kinetics of the chemical reaction in question.
COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 312.257.708-90 - YURI ALEXANDRE AOTO - NENHUMA
Membro Titular - Examinador(a) Interno ao Programa - 149.405.258-05 - KATHIA MARIA HONORIO - USP
Membro Titular - Examinador(a) Externo à Instituição - JOSÉ WALKIMAR DE MESQUITA CARNEIRO - UFF
Membro Suplente - Examinador(a) Externo à Instituição - RICARDO RODRIGUES DE OLIVEIRA JUNIOR - UFRJ
Membro Suplente - Examinador(a) Externo à Instituição - ANTONIO DE MACEDO FILHO - UESPI