A high‐level ab initio study of the N₂ + N₂ reaction channel

Abstract

A new six-dimensional (6D) global potential energy surface (PES) is proposed for the full range description of the interaction of the N2(1Σg+)+N2(1Σg+) system governing collisional processes, including N atom exchange. The related potential energy values were determined using high-level ab initio methods. The calculations were performed at a coupled-cluster with single and double and perturbative triple excitations level of theory in order to have a first full range picture of the PES. Subsequently, in order to accurately describe the stretching of the bonds of the two interacting N2 molecules by releasing the constraints of being considered as rigid rotors, for the same molecular geometries higher level of theory multi reference calculations were performed. Out of the calculated values a 6D 4-atoms global PES was produced for use in dynamical calculations. The ab initio calculations were made possible by the combined use of High Throughput Computing and High Performance Computing techniques within the frame of a computing grid empowered molecular simulator.

The effect of the intermolecular potential formulation on the state‐selected energy exchange rate coefficients in N2–N2 collisions

“…Moreover, range and strength of the interaction predicted by INTERPOT‐II for the main geometries of the N 2 –N 2 dimer are in scale with previous ab initio results (and even in better agreement with the outcomes of very recent ab initio data and ab initio‐ based PESs of Refs. ).…”

“…This is, indeed, our ultimate goal also in investigating the N 2 +N 2 collision processes which are a building block of the more complex virtual experiment planned a few years ago within the project Phys4entry in collaboration with other research groups . This article focuses, as already mentioned, on the first steps of the simulation concerned with the validation of the proposed semiempirical formulations of the N 2 + N 2 PES, the singling out of the role played by its components in determining the value of the observable properties of the system related to V‐V exchange and the preparation of a procedure carrying out a similar analysis on more complex potentials incorporating a better description of the exchange and fragmentation channels (such as the ones that just appeared in the literature).…”

Molecular Physics of Elementary Processes Relevant to Hypersonics: Atom-Molecule, Molecule-Molecule and Atoms-Surface Processes

“…The combined use of the above mentioned complete PES and QCT techniques makes up a versatile computational tool for extended studies of CO 2 -CO 2 collision dynamics, which is being ported on high performance computing facilities and implemented in the European Grid Infrastructure, through the COMPCHEM VO [16], while a similar procedure is being adopted to get efficient tools to study also reactive processes (see, e.g., refs. [56,57]). The processes considered here are:…”

Energy transfer dynamics and kinetics of elementary processes (promoted) by gas‐phase CO2‐N2 collisions: Selectivity control by the anisotropy of the interaction

“…This idea of representing the interaction in terms of bond-bond contributions provides a solid ground for making the potential energy functional flexible, as it has been satisfactorily tested on various systems (see for instance Refs. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]), and is applied here for the first time to CO 2 -N 2 .…”