# grandThermodynamicPotential¶

grandThermodynamicPotential(defects_list, temperature=None, absolute_error=None, max_steps=None, relative_error=None, root_mean_square_error=None, discard_faulty=None)

Implement a way to compute GTP.

Parameters: defects_list (list of ( VacancyList | SubstitutionalList | InterstitialList | SplitInterstitialList | DefectPairList | DefectClusterList) – List of calculated defects. Usually one vacancy per element, one antisite per element and one interstitial per element is needed. temperature (PhysicalQuantity of type temperature.) – Temperature Default: 300 Kelvin absolute_error (PhysicalQuantity of type energy) – Defines the convergence criterion to stop the iteration when the absolute errors of the chemical potential solutions are smaller than the given number. Default: 1e-5 eV max_steps (int) – Defines the maximum number of iterations in which to solve the equations using the Newton method. Default: 50 relative_error (float) – Defines the convergence criterion to stop the iteration when the relative errors of the chemical potential solutions are smaller than the given number. Default: 1e-4 root_mean_square_error (float) – Defines the convergence criterion to stop the iteration when the root-mean-square (RMS) error is smaller than the given number. Default: 1e-12 discard_faulty (bool) – Whether faulty (non converged) defect simulations are discarded Default: True A list of filled AtomicChemicalPotential

## Notes¶

For a comprehensive description on the use of this class to compute chemical potentials see Chemical Potentials in Compound Materials

## Example¶

The following few lines show how to compute the chemical potential of a TiN compound system when the native defects (vacancies, interstitials and antisites) are present. Then, the potentials are used to update the material specifications:

# update and run all defects
defect_lists=[vacancy, Ti_N, N_Ti, Ti_interstitial, N_interstitial]
updateAllDefectsAndTransitions(defect_lists=defect_lists, processes_per_defect=14)

# calculate atomic chemical potentials using GTP
GTP_potentials=grandThermodynamicPotential(defect_lists)

# Update GTP potentials in reference system
TiN_GTP_specifications = TiN(atomic_chemical_potentials=GTP_potentials)