Mo, Huangrui;
You, Xiaoqing;
Luo, Kai Hong;
Robertson, Struan H;
(2022)
On the determination of Lennard-Jones parameters for polyatomic molecules.
Physical Chemistry Chemical Physics
, 24
(17)
pp. 10147-10159.
10.1039/d2cp00065b.
Preview |
Text
Luo_Luo 2022 PCCP accepted.pdf - Accepted Version Download (10MB) | Preview |
Abstract
Characterizing the key length and energy scales of intermolecular interactions, Lennard-Jones parameters, i.e., collision diameter and well depth, are prerequisites for predicting transport properties and rate constants of chemical species in dilute gases. Due to anisotropy in molecular structures, Lennard-Jones parameters of many polyatomic molecules are only empirically estimated or even undetermined. This study focuses on determining the effective Lennard-Jones parameters between a polyatomic molecule and a bath gas molecule from interatomic interactions. An iterative search algorithm is developed to find orientation-dependent collision diameters and well depths on intermolecular potential energy surfaces. An orientation-averaging rule based on characteristic variables is proposed to derive the effective parameters. Cross-interaction parameters for twelve hydrocarbons with varying molecular shapes, including long-chain and planar ones, interacting with four bath gases He, Ar, N2, and O2 are predicted and reported. Three-dimensional parametric surfaces are constructed to quantitatively depict molecular anisotropy. Algorithmic complexity analysis and numerical experiments demonstrate that the iterative search algorithm is robust and efficient. By using the latest experimental diffusion data, it is found that the proposed orientation-averaging rule improves the prediction of cross-interaction Lennard-Jones parameters for polyatomic molecules, including for long-chain molecules that challenge the consistency of previous methods. By introducing characteristic variables, the present study shows a new route to determining effective Lennard-Jones parameters for polyatomic molecules.
| Type: | Article |
|---|---|
| Title: | On the determination of Lennard-Jones parameters for polyatomic molecules |
| Location: | England |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1039/d2cp00065b |
| Publisher version: | https://doi.org/10.1039/D2CP00065B |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10149494 |
Archive Staff Only
 |
View Item |
