Work

Dynamics Calculations of the Flexibility and Vibrational Spectrum of the Linear Alkane C 14 H 30 , Based on Machine-Learned Potentials

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Hydrocarbons are the central feedstock of fuels, solvents, lubricants, and the starting materials for many synthetic materials, and thus the physical properties of hydrocarbons have received intense study. Among these, the molecular flexibility and the power and infrared spectroscopies are the focus of this paper. These are examined for the linear alkane C 14 H 30 using molecular dynamics (MD) calculations and recent machine-learned potentials. All MD calculations are microcanonical and start at the global linear minimum. The radius of gyration, the number of gauche bond conformations and the distributions of all C–C distances are reported as a function of the total internal energy and as a function of time. These are compared to the power spectra and to the double harmonic spectra of stationary points. Spectral features of the double harmonic spectra smoothly track structural differences, measured by the number of gauche conformations in the molecule. Preliminary calculations using the quantum local mode model for the CH-stretch are presented and satisfactorily capture anharmonic effects.

Source: The Journal of Physical Chemistry A

DOI: 10.1021/acs.jpca.4c06943

Authors: Chen Qu, Paul L. Houston, Riccardo Conte, Joel M. Bowman

Institutions: Georgia Institute of Technology, Cornell University, University of Milan, Emory University

Language: English

Topic: Spectroscopy and Quantum Chemical Studies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Aeronautics and Space Administration, Nuclear Safety and Security Commission

Award: G8671728988