Predictive thermodynamics for ionic solids and liquids

Area of Science:

• Physical Chemistry
• Materials Science
• Computational Chemistry

Background:

• Thermodynamic parameter estimation for ionic materials is often challenging.
• Existing methods may require significant computational resources or expertise.
• Accurate thermodynamic data is crucial for predicting material behavior and feasibility of reactions.

Purpose of the Study:

• To introduce and demonstrate accessible tools for estimating thermodynamic parameters of ionic materials.
• To provide a simplified approach to calculating key thermodynamic and thermomechanical properties.
• To extend these methods to various ionic systems, including liquids and novel materials.

Main Methods:

• Volume-based thermodynamics (VBT) and thermodynamic difference rules (TDR).
• Supplemented by the simple salt approximation (SSA) and single-ion values.
• Application to calculate properties like enthalpy, entropy, heat capacity, and Gibbs energy.

Main Results:

• Successful estimation of elusive thermodynamic parameter values for solid and liquid ionic materials, hydrates, and solvates.
• Methods are largely independent of crystal structure, enabling application to ionic liquids and new materials.
• Validation through application to K2SnCl6, showing good agreement with experimental results.

Conclusions:

• VBT and TDR offer powerful yet simple methods for thermodynamic analysis.
• These techniques do not require high-level computational expertise or expensive tools.
• The established connection between formula unit volume and thermodynamic parameters is a key advance.