New rotational rate coefficients computation of MgC3N(X2Σ+) by collision with He(1S).

Determining physical conditions in interstellar environments requires reliable estimation of collisional data for molecules detected in space. In this work, we report a rate coefficients calculation of MgC3N(X 2Σ+) induced by collision with He. This study is based on a new 2D potential energy surface (2D-PES), obtained from the explicitly correlated restricted open-shell coupled cluster approach with single, double, and perturbative triple excitation (rccsd(t)-f12) and the aug-cc-pVTZ basis sets. The MgC3N–He PES presents a global minimum with a well depth of −45.6 cm−1. Based on this interaction potential, we derived the excitation cross-sections using the close-coupling quantum time-independent formalism for total energies ≤500 cm−1 and N ≤ 40. These cross-sections were then integrated on a Maxwell–Boltzmann distribution of kinetic energies to obtain the collisional (de)-excitation rate coefficients for thermal temperature below 100 K. A non-LTE radiative transfer calculation was performed using the present collisional rates in order to estimate their impact on the abundance of MgC3N. These collisional data can help astronomers for the detection and an accurate determination of MgC3N abundance in the investigated interstellar clouds. [ABSTRACT FROM AUTHOR]