The Binding Energies of Atoms on Amorphous Silicate Dust: A Computational Study

Fuente: arXiv
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Main Authors: Hansson, Kristoffer, Sameera, W. M. C., Esmerian, Clarke J., Bossion, Duncan, Andersson, Stefan, Aalto, Susanne, Vlemmings, Wouter, Knudsen, Kirsten K., Nyman, Gunnar
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Published: 2025
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author Hansson, Kristoffer
Sameera, W. M. C.
Esmerian, Clarke J.
Bossion, Duncan
Andersson, Stefan
Aalto, Susanne
Vlemmings, Wouter
Knudsen, Kirsten K.
Nyman, Gunnar
author_facet Hansson, Kristoffer
Sameera, W. M. C.
Esmerian, Clarke J.
Bossion, Duncan
Andersson, Stefan
Aalto, Susanne
Vlemmings, Wouter
Knudsen, Kirsten K.
Nyman, Gunnar
contents Context. We investigate the binding energies of atoms to interstellar dust particles, which play a key role in their growth and evolution, as well as for the chemical reactions on their surfaces. Aims. We aim to compute the binding energies of abundant atoms in the interstellar medium (C, N, O, Mg, Al, Si, S, Ca, Fe, and Ni) to silicate dust. Methods. We used the Geometries, Frequencies, and Non-covalent Interactions Tight Binding (GFN1-xTB) method to compute the binding energies. An FeMgSiO$_4$ periodic surface model, containing 81 local minima on the surface, was used. Results. A range of binding energies was found for each element. The median of the binding energies follows the order Si (14.8 eV) > Al (12.8 eV) > Ca (12.7 eV) > C (9.5 eV) > O (8.1 eV) > N (6.2 eV) > Fe (6.0 eV) > S (5.2 eV) > Mg (2.4 eV). The probability distribution of binding energies for each element except Ca is statistically consistent with a log-normal distribution. Conclusions. In general, Si, Ca, and Al atoms have large binding energies. Thus, these atoms can stay on the silicate dust particles at high temperatures. The binding energies of the other atoms, C, N, O, Mg, S, Fe and Ni, are relatively weak. However, the computed binding energies for these elements are still far stronger than the energies associated with dust temperatures typical of the ambient interstellar medium (ISM), suggesting that silicate grains are generally stable against sublimation. We estimate sublimation temperatures for silicate grains to range from 1600 K to 3000K depending on assumed grain size and lifetime. These binding energies on silicate dust grains, estimated from first principles for the first time, provide invaluable input to models of dust evolution and dust-catalyzed chemical reactions in the interstellar medium.
format Preprint
id arxiv_https___arxiv_org_abs_2508_19339
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Binding Energies of Atoms on Amorphous Silicate Dust: A Computational Study
Hansson, Kristoffer
Sameera, W. M. C.
Esmerian, Clarke J.
Bossion, Duncan
Andersson, Stefan
Aalto, Susanne
Vlemmings, Wouter
Knudsen, Kirsten K.
Nyman, Gunnar
Astrophysics of Galaxies
Materials Science
Context. We investigate the binding energies of atoms to interstellar dust particles, which play a key role in their growth and evolution, as well as for the chemical reactions on their surfaces. Aims. We aim to compute the binding energies of abundant atoms in the interstellar medium (C, N, O, Mg, Al, Si, S, Ca, Fe, and Ni) to silicate dust. Methods. We used the Geometries, Frequencies, and Non-covalent Interactions Tight Binding (GFN1-xTB) method to compute the binding energies. An FeMgSiO$_4$ periodic surface model, containing 81 local minima on the surface, was used. Results. A range of binding energies was found for each element. The median of the binding energies follows the order Si (14.8 eV) > Al (12.8 eV) > Ca (12.7 eV) > C (9.5 eV) > O (8.1 eV) > N (6.2 eV) > Fe (6.0 eV) > S (5.2 eV) > Mg (2.4 eV). The probability distribution of binding energies for each element except Ca is statistically consistent with a log-normal distribution. Conclusions. In general, Si, Ca, and Al atoms have large binding energies. Thus, these atoms can stay on the silicate dust particles at high temperatures. The binding energies of the other atoms, C, N, O, Mg, S, Fe and Ni, are relatively weak. However, the computed binding energies for these elements are still far stronger than the energies associated with dust temperatures typical of the ambient interstellar medium (ISM), suggesting that silicate grains are generally stable against sublimation. We estimate sublimation temperatures for silicate grains to range from 1600 K to 3000K depending on assumed grain size and lifetime. These binding energies on silicate dust grains, estimated from first principles for the first time, provide invaluable input to models of dust evolution and dust-catalyzed chemical reactions in the interstellar medium.
title The Binding Energies of Atoms on Amorphous Silicate Dust: A Computational Study
topic Astrophysics of Galaxies
Materials Science
url https://arxiv.org/abs/2508.19339