pymatgen.entries.mixing_scheme module

This module implements Compatibility corrections for mixing runs of different functionals.

class MaterialsProjectDFTMixingScheme(structure_matcher: StructureMatcher = <pymatgen.analysis.structure_matcher.StructureMatcher object>, run_type_1: str = 'GGA(+U)', run_type_2: str = 'R2SCAN', compat_1: Compatibility | None = <pymatgen.entries.compatibility.cached_class.<locals>._decorated object>, compat_2: Compatibility | None = None, fuzzy_matching: bool = True)[source]

Bases: pymatgen.entries.compatibility.Compatibility

This class implements the Materials Project mixing scheme, which allows mixing of energies from different DFT functionals. Note that this should only be used for VASP calculations using the MaterialsProject parameters (e.g. MPRelaxSet or MPScanRelaxSet). Using this compatibility scheme on runs with different parameters may lead to unexpected results.

This is the scheme used by the Materials Project to generate Phase Diagrams containing a mixture of GGA(+U) and R2SCAN calculations. However in principle it can be used to mix energies from any two functionals.

Instantiate the mixing scheme. The init method creates a generator class that contains relevant settings (e.g., StrutureMatcher instance, Compatibility settings for each functional) for processing groups of entries.

Parameters
  • structure_matcher (StructureMatcher) – StructureMatcher object used to determine whether calculations from different functionals describe the same material.

  • run_type_1

    The first DFT run_type. Typically this is the majority or run type or the “base case” onto which the other calculations are referenced. Valid choices are any run_type recognized by Vasprun.run_type, such as “LDA”, “GGA”, “GGA+U”, “PBEsol”, “SCAN”, or “R2SCAN”. The class will ignore any entries that have a run_type different than run_type_1 or run_type_2.

    The list of run_type_1 entries provided to process_entries MUST form a complete Phase Diagram in order for the mixing scheme to work. If this condition is not satisfied, processing the entries will fail.

    Note that the special string “GGA(+U)” (default) will treat both GGA and GGA+U calculations as a single type. This option exists because GGA/GGA+U mixing is already handled by MaterialsProject2020Compatibility.

  • run_type_2 – The second DFT run_type. Typically this is the run_type that is ‘preferred’ but has fewer calculations. If run_type_1 and run_type_2 calculations exist for all materials, run_type_2 energies will be used (hence the ‘preferred’ status). The class will ignore any entries that have a run_type different than run_type_1 or run_type_2.

  • compat_1 – Compatibility class used to pre-process entries of run_type_1. Defaults to MaterialsProjectCompatibility2020.

  • compat_2 – Compatibility class used to pre-process entries of run_type_2. Defaults to None.

  • fuzzy_matching – Whether to use less strict structure matching logic for diatomic elements O2, N2, F2, H2, and Cl2 as well as I and Br. Outputs of DFT relaxations using different functionals frequently fail to structure match for these elements even though they come from the same original material. Fuzzy structure matching considers the materials equivalent if the formula, number of sites, and space group are all identical. If there are multiple materials of run_type_2 that satisfy these criteria, the one with lowest energy is considered to match.

static display_entries(entries)[source]

Generate a pretty printout of key properties of a list of ComputedEntry

get_adjustments(entry, mixing_state_data: Optional[pandas.core.frame.DataFrame] = None)[source]

Returns the corrections applied to a particular entry. Note that get_adjustments is not intended to be called directly in the R2SCAN mixing scheme. Call process_entries instead, and it will pass the required arguments to get_adjustments.

Parameters
  • entry – A ComputedEntry object. The entry must be a member of the list of entries used to create mixing_state_data.

  • mixing_state_data – A DataFrame containing information about which Entries correspond to the same materials, which are stable on the phase diagrams of the respective run_types, etc. Can be generated from a list of entries using MaterialsProjectDFTMixingScheme.get_mixing_state_data. This argument is included to facilitate use of the mixing scheme in high-throughput databases where an alternative to get_mixing_state_data is desirable for performance reasons. In general, it should always be left at the default value (None) to avoid inconsistencies between the mixing state data and the properties of the ComputedStructureEntry.

Returns

Energy adjustments to be applied to entry.

Return type

[EnergyAdjustment]

Raises

CompatibilityError if the DFT mixing scheme cannot be applied to the entry.

get_mixing_state_data(entries: list[pymatgen.entries.computed_entries.ComputedStructureEntry], verbose: bool = False)[source]

Generate internal state data to be passed to get_adjustments.

Parameters

entries – The list of ComputedStructureEntry to process. It is assumed that the entries have already been filtered using _filter_and_sort_entries() to remove any irrelevant run types, apply compat_1 and compat_2, and confirm that all have unique entry_id.

Returns

A pandas DataFrame that contains information associating structures from

different functionals with specific materials and establishing how many run_type_1 ground states have been computed with run_type_2. The DataFrame contains one row for each distinct material (Structure), with the following columns:

formula: str the reduced_formula spacegroup: int the spacegroup num_sites: int the number of sites in the Structure entry_id_1: the entry_id of the run_type_1 entry entry_id_2: the entry_id of the run_type_2 entry run_type_1: Optional[str] the run_type_1 value run_type_2: Optional[str] the run_type_2 value energy_1: float or nan the ground state energy in run_type_1 in eV/atom energy_2: float or nan the ground state energy in run_type_2 in eV/atom is_stable_1: bool whether this material is stable on the run_type_1 PhaseDiagram hull_energy_1: float or nan the energy of the run_type_1 hull at this composition in eV/atom hull_energy_2: float or nan the energy of the run_type_1 hull at this composition in eV/atom

None: Returns None if the supplied ComputedStructureEntry are insufficient for applying

the mixing scheme.

Return type

DataFrame

process_entries(entries: ComputedStructureEntry | ComputedEntry | list, clean: bool = True, verbose: bool = True, mixing_state_data=None)[source]

Process a sequence of entries with the DFT mixing scheme. Note that this method will change the data of the original entries.

Parameters
  • entries

    ComputedEntry or [ComputedEntry]. Pass all entries as a single list, even if they are computed with different functionals or require different preprocessing. This list will automatically be filtered based on run_type_1 and run_type_2, and processed according to compat_1 and compat_2.

    Note that under typical use, when mixing_state_data=None, the entries MUST be ComputedStructureEntry. They will be matched using structure_matcher.

  • clean – bool, whether to remove any previously-applied energy adjustments. If True, all EnergyAdjustment are removed prior to processing the Entry. Default is True.

  • verbose – bool, whether to print verbose error messages about the mixing scheme. Default is True.

  • mixing_state_data – A DataFrame containing information about which Entries correspond to the same materials, which are stable on the phase diagrams of the respective run_types, etc. If None (default), it will be generated from the list of entries using MaterialsProjectDFTMixingScheme.get_mixing_state_data. This argument is included to facilitate use of the mixing scheme in high-throughput databases where an alternative to get_mixing_state_data is desirable for performance reasons. In general, it should always be left at the default value (None) to avoid inconsistencies between the mixing state data and the properties of the ComputedStructureEntry in entries.

Returns

A list of adjusted entries. Entries in the original list which are not compatible are excluded.