MARATTO

article · AppliedMath

Ro-Vibrational and Pure Vibrational Partition Functions and Thermodynamic Properties in an Eckart-like Potential Model

2026Open accessBowen University

In plain language

An investigation of a quantum system governed by an Eckart-like potential model provides exact analytical expressions for energy eigenvalues by solving the radial Schrödinger equation using the Greene-Aldrich approximation. By explicitly including the rotational quantum number, the ro-vibrational partition function is derived to determine vital thermodynamic functions such as Gibbs free energy, entropy, and enthalpy. Numerical evaluations indicate that the partition function increases continuously with temperature, Gibbs free energy declines as anticipated by statistical thermodynamics, entropy levels off at elevated temperatures, and enthalpy shows convex growth with added thermal energy. Parametric analysis establishes that adjusting potential characteristics, including screening parameters, permits the controlled manipulation of thermodynamic properties. The resulting formulations generalise earlier models, recover the Hulthén potential in limiting scenarios, and advance the theoretical comprehension of ro-vibrational statistical mechanics in exponential-type potentials.

Key takeaways

  • Analytical energy eigenvalues were derived for an Eckart-like potential model using the Greene-Aldrich approximation scheme.
  • The ro-vibrational partition function was formulated by explicitly accounting for rotational quantum numbers.
  • Calculations demonstrated monotonic growth in the partition function, declining Gibbs free energy, high-temperature entropy saturation, and convex enthalpy growth.
  • Adjusting potential parameters, such as the screening parameter, enables the controlled tuning of thermodynamic properties.
  • The model generalises existing theoretical frameworks and reproduces the Hulthén potential under specific conditions.

Why it matters

Understanding the thermodynamic behaviour of molecular systems requires accurate mathematical models that incorporate both rotational and vibrational energy states. By providing closed-form solutions for an Eckart-like potential, this theoretical framework enhances the precision of statistical thermodynamic calculations, offering clearer insights into how thermal energy influences molecular stability, entropy, and heat capacity under varied physical conditions.

Commercialisation angle

The abstract does not indicate an application pathway.

AI-generated from the published abstract. Always read the original work before citing.

Abstract

This study obtained the energy levels and examined the partition function (Z) of a quantum system described by an Eckart-like potential model. By adopting the Greene–Aldrich approximation scheme for the centrifugal term, the radial Schrödinger equation (SE) is solved and the analytic expression of the energy eigenvalues is obtained. The ro-vibrational Z is computed by explicitly incorporating the rotational quantum number, a feature often neglected or misapplied in many studies. This result is used to evaluate the key thermodynamic properties (TP), including the Gibbs free energy (G), entropy (S), and enthalpy (H). Numerical analysis reveals that the Z increases monotonically with temperature, while the G decreases in accordance with statistical thermodynamics. The S exhibits saturation-like behaviour at higher temperatures, while the H displays convex growth with increasing thermal energy. Parametric studies demonstrate that the Eckart-like potential allows for the controlled tuning of TP, with variations in the potential parameters, including the screening parameter, having distinct effects. The results generalise existing models, reproduce the Hulthén potential under specific conditions, show the effect of the rotational quantum number of TP, and provide new insights into the ro-vibrational statistical mechanics of exponential-type potentials.

Research topics

  • Quantum Mechanics and Non-Hermitian Physics
  • Statistical Mechanics and Entropy
  • Thermoelastic and Magnetoelastic Phenomena

Sustainable Development Goals

Read the original research

This page summarises published work. The authoritative version sits with the publisher.

DOI: 10.3390/appliedmath6080130

Is something wrong with this record? Report it or request removal.

Discussion

Discuss this research

Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.

No discussion yet. Open the first thread.