dorsal/arxiv
View SchemaMolecular Dynamics Simulation of Vibrational Phase Relaxation along the Critical Isochore of Nitrogen : The Role of Local Density Fluctuations
| Authors | Swapan Roychowdhury, Biman Bagchi |
|---|---|
| Categories | |
| ArXiv ID | physics/0210039 |
| URL | https://arxiv.org/abs/physics/0210039 |
Abstract
Vibrational dephasing of nitrogen molecule is known to show highly interesting anomalies near its gas-liquid critical point. Here we present theoretical and computational studies of the Raman linewidth of nitrogen along the critical isochore. The linewidth is found to have a lambda shaped temperature dependence near the critical point. As observed in experimental studies, the calculated lineshape becomes Gaussian as the critical temperature ($T_{c}$) is approached. Both the present simulation and a mode coupling theory (MCT) analysis show that the slow decay of the enhanced density fluctuations near the critical point (CP), probed at the sub-picosecond time scales by vibrational frequency modulation, along with an enhanced vibration-rotation coupling, are the main causes of the observed anomalies.
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"date_created": "2026-03-02T18:00:39.768000Z",
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"abstract": "Vibrational dephasing of nitrogen molecule is known to show highly\ninteresting anomalies near its gas-liquid critical point. Here we present\ntheoretical and computational studies of the Raman linewidth of nitrogen along\nthe critical isochore. The linewidth is found to have a lambda shaped\ntemperature dependence near the critical point. As observed in experimental\nstudies, the calculated lineshape becomes Gaussian as the critical temperature\n($T_{c}$) is approached. Both the present simulation and a mode coupling theory\n(MCT) analysis show that the slow decay of the enhanced density fluctuations\nnear the critical point (CP), probed at the sub-picosecond time scales by\nvibrational frequency modulation, along with an enhanced vibration-rotation\ncoupling, are the main causes of the observed anomalies.",
"arxiv_id": "physics/0210039",
"authors": [
"Swapan Roychowdhury",
"Biman Bagchi"
],
"categories": [
"physics.chem-ph"
],
"title": "Molecular Dynamics Simulation of Vibrational Phase Relaxation along the Critical Isochore of Nitrogen : The Role of Local Density Fluctuations",
"url": "https://arxiv.org/abs/physics/0210039"
},
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