Related Experiment Video
Updated: May 30, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Quantum diffusive dynamics of macromolecular transitions
S a Beccara1, G Garberoglio, P Faccioli
1Dipartimento di Fisica, Università degli Studi di Trento, Via Sommarive 14, Povo (Trento) I-38123, Italy
Abstract:
We study the role of quantum fluctuations of atomic nuclei in the real-time dynamics of non-equilibrium macro-molecular transitions. To this goal we introduce an extension of the dominant reaction pathways formalism, in which the quantum corrections to the classical overdamped Langevin dynamics are rigorously taken into account to order ħ(2). We first illustrate our approach in simple cases, and compare with the results of the instanton theory. Then we apply our method to study the C7(eq) → C7(ax) transition of alanine dipeptide. We find that the inclusion of quantum fluctuations can significantly modify the reaction mechanism for peptides. For example, the energy difference which is overcome along the most probable pathway is reduced by as much as 50%.
Related Concept Videos
Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion
Transition State Theory
The de Broglie Wavelength
Phase Transitions: Vaporization and Condensation
Protein Dynamics in Living Cells
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Distribution of Molecular Speeds

