## Project

OpenCalphad is an open-source code for performing
thermodynamic calculations using the Calphad approach. The
code implements several different thermodynamic models which
allow the description of thermodynamic state functions, such
as the Gibbs energy, as a function of temperature, pressure
and composition. By minimizing the Gibbs (or Helmholtz)
energy, the equilibrium state can be determined for
multicomponent systems for a flexible set of conditions.
In subsequent steps phase diagrams and many other types
of diagrams can be computed.

In the present version, the code can read thermodynamic databases using the most popular “TDB” format. The software can perform equilibrium calculations for multicomponent systems and show several thermodynamic properties under different conditions. The Compound Energy Formalism (CEF) and the partially ionic 2-sublattice liquid (I2SL) models with magnetic contributions have been implemented and new models will be added in the future.

### Publications about and related to OpenCalphad

1. H L Lukas, S G Fries and B Sundman, * Computational
Thermodynamics, the CALPHAD method *, Cambridge Univ
Press (2007)

2. B Sundman, U R Kattner, M Palumbo and S G Fries, *
OpenCalphad - a free thermodynamic software*, Integ Mat
Manu Innov, (2015) 4:1

3. B Sundman, X-L Liu and H Ohtani, *The implementation
of an algorithm to calculate equilibria for multi-component
systems with non-ideal phases in a free software*, Comp
Mat Sci, (2015), 211-137

4. B Sundman, U R Kattner, C Sigli, M Stratmann, R Le
Tellier, M Palumbo and S G Fries, *The OpenCalphad
thermodynamic software interface*, Comp Mat Sci, (2016),
188&-196

5. A van de Walle, R Sun, Q-J Hong and S
Kadkhodaei, *Software tools for high througput CALPHAD from
first-principles data*, Calphad, (2017), 70-81

6. B Sundman, Q Chen and Y Du, *A review of Calphad
Modeling of Ordered Phases*, J Phase Equilib Diffus, (2018)
39:678-693

7. J Li, B Sundman, J G M Winkelman, A I Vakis and F Picchioni,
*Implementation of the UNIQUAC model in the OpenCalphad
software*, Fluid Phase Equil, (2020), 112398

8. J Herrnring, B Sundman and B
Klusemann, *Diffusion-driven microstructure evolution in
OpenCalphad*, Comp Mat Sci, (2020), 109-236

9. C Introini, J Sercombe and B Sundman, * Development of
a robust, accurate and efficient coupling between
PLEIADES/ALCYONE 2.1 fuel performance code and the
OpenCalphad thermo-chemical solver*, Nucl Eng and Des,
(2020) , 110818

10. K Samuelsson, J-C Dumas, B Sundman, J Lamontangne and C Gueneau,
*Simulation of the chemical state of high burnup (U,Pu)O2
fuel in fast reactors based on thermodynamic
calculations*, J Nucl Mat, (2020), 151969

11. B Sundman, U R Kattner, M Hillert, M Selleby, J Agren, S
Bigdeli, Q Chen, A Dinsdale, B Hallsted, A Khvan, H Mao and R
Otis, *A method for handling the extrapolation of solid
crystalline phases to temperatures far above their melting
point*, Calphad, (2020) 101737

12. Z He, B Kaplan, H Mao and M Selleby, *The third
generation Calphad description of Al-C including revisions
of pure Al and C*, Calphad, (2021) 102250

13. B Sundman, N Dupin and B Hallstedt, *Algorithms
useful for calculating multi-component equilibria, phase
diagrams and other kinds of diagrams*, Calphad, (2021)
102330

14. C Introini, J Sercombe, I Ramiere and R Le
Tellier, *Phase field modeling with the TAF-ID of
inciplient melting and oxygen transport in nuclear fuel during
power transients*, J Nucl Mat, (2021)151173

15. J Herrnring, B Sundman, P Staron and B
Klusemann, *Modeling precipitation kinetics for multi-phase
and multi-component system using particle size distributions
via moving grid technique*, Acta Mat, (2021) 117053