# Thermodynamic modeling

The structure and composition of Earth's interior provide the fundamental information for scientists to interpret geological activities on the surface, and to understand the formation and evolution of the planet. However, the interior of the Earth is largely inaccessible to direct observation, and the deepest drill holes (~12 km) are only 0.1 % of the Earth's radius (6370 km). Thermodynamic models can be applied to predict the physical properties (e.g., volume, density, velocity) and phase transitions of Earth's materials, which provide indirect information of Earth’s internal structure and composition. I develop a Python package with a graphical user interface, **MinPhy**, to calculate and plot the volume of one phase at high pressure temperature conditions and the equilibrium boundary between two phases.

**MinPhy** provides **two** thermal equation of state models to calculate the volume of one phase at high pressure temperature conditions:

- Third-order high-temperature Birch-Murnaghan equation of state
- Mie-Grüneisen-Debye equation of state

and provides **three** models to calculate the minimum of the Gibbs free energy of two phases:

- Caloric-Murnaghan Model
- Caloric-Modified-Tait Model
- Birch-Murnaghan-Mie-Grüneisen-Debye Model