dorsal/arxiv
View SchemaTheoretical study of finite temperature spectroscopy in van der Waals clusters. I. Probing phase changes in CaAr_n
| Authors | F. Calvo, F. Spiegelman, M. C. Heitz |
|---|---|
| Categories | |
| ArXiv ID | physics/0212062 |
| URL | https://arxiv.org/abs/physics/0212062 |
| DOI | 10.1063/1.1566950 |
Abstract
The photoabsorption spectra of calcium-doped argon clusters CaAr_n are investigated at thermal equilibrium using a variety of theoretical and numerical tools. The influence of temperature on the absorption spectra is estimated using the quantum superposition method for a variety of cluster sizes in the range 6<=n<=146. At the harmonic level of approximation, the absorption intensity is calculated through an extension of the Gaussian theory by Wadi and Pollak [J. Chem. Phys. vol 110, 11890 (1999)]. This theory is tested on simple, few-atom systems in both the classical and quantum regimes for which highly accurate Monte Carlo data can be obtained. By incorporating quantum anharmonic corrections to the partition functions and respective weights of the isomers, we show that the superposition method can correctly describe the finite-temperature spectroscopic properties of CaAr_n systems. The use of the absorption spectrum as a possible probe of isomerization or phase changes in the argon cluster is discussed at the light of finite-size effects.
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"abstract": "The photoabsorption spectra of calcium-doped argon clusters CaAr_n are\ninvestigated at thermal equilibrium using a variety of theoretical and\nnumerical tools. The influence of temperature on the absorption spectra is\nestimated using the quantum superposition method for a variety of cluster sizes\nin the range 6\u003c=n\u003c=146. At the harmonic level of approximation, the absorption\nintensity is calculated through an extension of the Gaussian theory by Wadi and\nPollak [J. Chem. Phys. vol 110, 11890 (1999)]. This theory is tested on simple,\nfew-atom systems in both the classical and quantum regimes for which highly\naccurate Monte Carlo data can be obtained. By incorporating quantum anharmonic\ncorrections to the partition functions and respective weights of the isomers,\nwe show that the superposition method can correctly describe the\nfinite-temperature spectroscopic properties of CaAr_n systems. The use of the\nabsorption spectrum as a possible probe of isomerization or phase changes in\nthe argon cluster is discussed at the light of finite-size effects.",
"arxiv_id": "physics/0212062",
"authors": [
"F. Calvo",
"F. Spiegelman",
"M. C. Heitz"
],
"categories": [
"physics.chem-ph",
"physics.atm-clus"
],
"doi": "10.1063/1.1566950",
"title": "Theoretical study of finite temperature spectroscopy in van der Waals clusters. I. Probing phase changes in CaAr_n",
"url": "https://arxiv.org/abs/physics/0212062"
},
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