dorsal/arxiv
View SchemaAn ab initio path integral Monte Carlo simulation method for molecules and clusters: application to Li_4 and Li_5^+
| Authors | Ruben O. Weht, Jorge Kohanoff, Dario A. Estrin, Charusita Chakravarty |
|---|---|
| Categories | |
| ArXiv ID | physics/9802020 |
| URL | https://arxiv.org/abs/physics/9802020 |
| DOI | 10.1063/1.476331 |
Abstract
A novel method for simulating the statistical mechanics of molecular systems in which both nuclear and electronic degrees of freedom are treated quantum mechanically is presented. The scheme combines a path integral description of the nuclear variables with a first-principles adiabatic description of the electronic structure. The electronic problem is solved for the ground state within a density functional approach, with the electronic orbitals expanded in a localized (Gaussian) basis set. The discretized path integral is computed by a Metropolis Monte Carlo sampling technique on the normal modes of the isomorphic ring-polymer. An effective short-time action correct to order $\tau^4$ is used. The validity and performance of the method are tested in two small Lithium clusters, namely Li$_4$ and Li$_5^+$. Structural and electronic properties computed within this fully quantum-mechanical scheme are presented and compared to those obtained within the classical nuclei approximation. Quantum delocalization effects are significant but tunneling turns out to be irrelevant at low temperatures.
{
"annotation_id": "dd411f5e-d07f-45a0-a9fa-e27de2d4fc81",
"date_created": "2026-03-02T18:01:20.787000Z",
"date_modified": "2026-03-02T18:01:20.787000Z",
"file_hash": "3809c4de7d80e8d57069583cc0c5366ee64586cf4f27a9e0dba439ce0e7cd81c",
"private": false,
"record": {
"abstract": "A novel method for simulating the statistical mechanics of molecular systems\nin which both nuclear and electronic degrees of freedom are treated quantum\nmechanically is presented. The scheme combines a path integral description of\nthe nuclear variables with a first-principles adiabatic description of the\nelectronic structure. The electronic problem is solved for the ground state\nwithin a density functional approach, with the electronic orbitals expanded in\na localized (Gaussian) basis set. The discretized path integral is computed by\na Metropolis Monte Carlo sampling technique on the normal modes of the\nisomorphic ring-polymer. An effective short-time action correct to order\n$\\tau^4$ is used. The validity and performance of the method are tested in two\nsmall Lithium clusters, namely Li$_4$ and Li$_5^+$. Structural and electronic\nproperties computed within this fully quantum-mechanical scheme are presented\nand compared to those obtained within the classical nuclei approximation.\nQuantum delocalization effects are significant but tunneling turns out to be\nirrelevant at low temperatures.",
"arxiv_id": "physics/9802020",
"authors": [
"Ruben O. Weht",
"Jorge Kohanoff",
"Dario A. Estrin",
"Charusita Chakravarty"
],
"categories": [
"physics.comp-ph",
"cond-mat.stat-mech",
"physics.atm-clus",
"physics.chem-ph"
],
"doi": "10.1063/1.476331",
"title": "An ab initio path integral Monte Carlo simulation method for molecules and clusters: application to Li_4 and Li_5^+",
"url": "https://arxiv.org/abs/physics/9802020"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "48d236fb-0ce7-4984-8f47-fc1fc2aa1266",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}