LIFE'S COSMIC HANDSHAKE: DFT AND TD-DFT PREDICTIONS FOR THE PROPERTIES OF ENSTATITE (MgSiO₃) MONOMERS AND DIMERS

Stelmach, Kamil B.

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Description

Title

LIFE'S COSMIC HANDSHAKE: DFT AND TD-DFT PREDICTIONS FOR THE PROPERTIES OF ENSTATITE (MgSiO₃) MONOMERS AND DIMERS

Author(s)

Stelmach, Kamil B.

Contributor(s)

• Garrod, Robin T.
• Dukes, Catherine A.

Issue Date

2023-06-20

Keyword(s)

• Electronic structure
• potential energy surfaces

Abstract

Silicates represent an understudied class of molecules in astrochemistry despite surfaces having been shown to have important chemical and physical effects. Clinoenstatite has been detected in interstellar spaceᵃ and is a major component of meteorites.ᵇ Clinoenstatite is also interesting because it has chiral faces.ᶜ Structural and spectral studies utilizing density functional theory (DFT) and time-dependent (TD-) DFT were conducted on the monomer and a nanosilicate dimer of enstatite first described in Valencia et al.ᵈ; in addition, a 2D chiral conformer of the dimer was also studied. The HSE06/aug-cc-pVQZ level of theory was chosen for optimization, frequency, and energy calculations. CAM-B3LYP and ωB97X-D3 function- als were used with the cc-pVQZ basis set in the TD-DFT calculations to obtain the UV-Vis and ECD spectra. We modeled each structure in its bare silicate form but also with H, H⁺, and H₂. Placing the neutral H on the 2D chiral enstatite conformer produces a 3D structure that makes it optically active. This provides a symmetry breaking mechanism for chiral silicates in the ISM.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Handle URL

https://hdl.handle.net/2142/122540

DOI

https://doi.org/10.15278/isms.2023.7017

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