Accurate DMBE potential-energy surface for CNO(2A″) and rate coefficients in C(3P)+NO collisions

M O Alves; C E M Gonçalves; J P Braga; V C Mota; A J C Varandas; B R L Galvão

doi:10.1063/5.0031199

Accurate DMBE potential-energy surface for CNO(²A″) and rate coefficients in C(³P)+NO collisions

J Chem Phys. 2021 Jan 21;154(3):034303. doi: 10.1063/5.0031199.

Authors

M O Alves¹, C E M Gonçalves², J P Braga², V C Mota³, A J C Varandas³, B R L Galvão¹

Affiliations

¹ Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Av. Amazonas 5253, 30421-169 Belo Horizonte, Minas Gerais, Brazil.
² Departamento de Química, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, Brazil.
³ Departamento de Física, Universidade Federal do Espírito Santo, 29075-910 Vitória, Brazil.

PMID: 33499610
DOI: 10.1063/5.0031199

Abstract

A realistic double many-body expansion potential energy surface (PES) is developed for the ²A″ state of the carbon-nitrogen-oxygen (CNO) system based on MRCI-F12/cc-pVQZ-F12 ab initio energies. The new PES reproduces the fitted points with chemical accuracy (root mean square deviation up to 0.043 eV) and explicitly incorporates long range energy terms that can accurately describe the electrostatic and dispersion interactions. Thermal rate coefficients were computed for the C(³P) + NO(²Π) reaction for temperatures ranging from 15 K to 10 000 K, and the values are compared to previously reported results. The differences are rationalized, and the major importance of long range forces in predicting the rate coefficients for barrierless reactions is emphasized.