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Thermodynamics and its correlation with dynamics in a mean-field model and pinned systems: A comparative study using
Ujjwal Kumar Nandi1, Palak Patel1, Mohd Moid2
1Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune 411008, India.
The Journal of Chemical Physics
|January 9, 2022
Summary
The thermodynamic integration (TI) method yields unphysical entropy results for a novel mean-field model, while two-phase thermodynamics (2PT) provides consistent, positive entropy values, highlighting method-dependent thermodynamic predictions.
Area of Science:
- Statistical Mechanics
- Computational Physics
Background:
- A novel mean-field model system with k additional pseudo-neighbors was recently introduced.
- Understanding the thermodynamics and dynamics of such systems is crucial for theoretical advancements.
Purpose of the Study:
- To conduct an extensive study of the thermodynamics and dynamics of the novel mean-field model.
- To investigate the correlation between thermodynamics and dynamics, particularly focusing on entropy calculation methods.
Main Methods:
- Thermodynamic integration (TI) method for entropy calculation.
- Two-phase thermodynamics (2PT) method for entropy calculation.
- Analysis of system dynamics, including collective and single-particle relaxation.
Main Results:
- The TI method produced unphysical results, predicting vanishing or negative configurational entropy.
- The 2PT method yielded positive entropy values consistent with Random First-Order Transition (RFOT) theory predictions.
- Increased pseudo-neighbor interactions (k) and particle pinning density amplified the discrepancy between TI and 2PT entropy calculations.
Conclusions:
- The TI method is unreliable for calculating entropy in this specific mean-field model, failing to capture physical behavior.
- The 2PT method offers a more robust approach for entropy calculation, aligning with established theoretical predictions like RFOT.
- The study underscores the critical impact of the chosen thermodynamic calculation method on the interpretation of system properties and dynamics.
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