electron_phonon.self_energy¶
(
- data_context,
- **kwargs
)
Access and analyze electron-phonon self-energy data.
This class provides methods to access, select, and analyze the electron-phonon self-energy. It allows you to retrieve various quantities such as eigenvalues, Debye-Waller and Fan self-energies, and scattering approximations for different selections of bands, k-points, and spin channel.
- Main features:
-
Retrieve self-energy data for specific bands, k-points and spin channels.
-
Convert self-energy data to dictionaries for further analysis.
-
Iterate over all available self-energy instances.
-
Examples
>>> elph_selfen = ElectronPhononSelfEnergy(raw_data)
>>> print(elph_selfen)
electron phonon self energy
>>> instance = elph_selfen[0]
>>> data = instance.to_dict()
chemical_potential_mu_tag
tuple
Return the chemical potential tag and values.
Returns
tuple- A tuple containing (tag_name, values_array) where tag_name is a string describing the chemical potential parameter and values_array contains the numerical values.
count
integer -- return number of occurrences of value
eigenvalues
np.ndarray
Return the eigenvalues from the raw data.
Returns
np.ndarray- Array containing eigenvalues for all k-points, bands, and spin channels.
index
integer -- return first index of value.
Raises ValueError if the value is not present.
Supporting start and stop arguments is optional, but recommended.
path
read
select
str) → list[SelfEnergyInstance]
Return a list of SelfEnergyInstance objects matching the selection.
Parameters
- selection:
str - String representing the selection criteria (e.g., “nbands_sum”, “selfen_approx”, “selfen_delta”) and the desired values for those properties
Returns
list[SelfEnergyInstance]- Instances that match the selection criteria.
selections
dict
Return a dictionary describing what options are available to read the electron self-energies.
Returns
dict- Dictionary containing available selection options with their possible values. Keys include selection criteria like “nbands_sum”, “selfen_approx”, “selfen_delta”.
to_dict
dict
Return a dictionary that lists how many accumulators are available
Returns
dict- Dictionary containing information about the available accumulators.
SelfEnergyInstance ¶
(
- parent,
- index
)
Represents a single instance of electron-phonon self-energy calculations. This class provides access to the electron-phonon self-energy data for a specific self-energy accumulator. It allows retrieval of various components of the self-energy, such as Debye-Waller and Fan terms.
Examples
>>> instance = ElectronPhononSelfEnergyInstance(parent, index=0)
>>> print(instance)
electron phonon self energy 0
>>> data = instance.to_dict()
>>> fan_value = instance.get_fan((iband, ikpt, isp))
debye_waller
SparseTensor
Return the Debye-Waller contribution to the electron-phonon self-energy as a sparse tensor.
Returns
SparseTensor- Sparse tensor containing Debye-Waller self-energy contributions for specific band, k-point, and spin combinations.
energies
SparseTensor
Return the energies at which the self energy was evaluated as a sparse tensor.
Returns
SparseTensor- Sparse tensor containing energy values for specific band, k-point, and spin combinations.
fan
SparseTensor
Return the Fan contribution to the electron-phonon self-energy as a sparse tensor.
Returns
SparseTensor- Sparse tensor containing Fan self-energy contributions for specific band, k-point, and spin combinations.
read
read_metadata
Dict[str, Any]
Read metadata for this instance.
The metadata contains information about the settings used for this instance, such as the number of bands included in the summation, the delta value used for the self-energy calculation, and the scattering approximation employed.
Returns
Dict[str, Any]- A dictionary containing the metadata for this instance. The keys correspond to settings in the INCAR file, and the values are the respective settings used.
self_energy
SparseTensor
Return the total electron-phonon self-energy as a sparse tensor.
Returns
SparseTensor- Sparse tensor containing the sum of Fan and Debye-Waller contributions for specific band, k-point, and spin combinations.
to_dict
dict
Convert the electron-phonon self-energy instance to a dictionary.
Returns
dict- Dictionary containing metadata, eigenvalues, fan terms, debye_waller terms, and energies for this self-energy instance.
SparseTensor ¶
(
- band_kpoint_spin_index,
- band_start,
- tensor
)
A sparse tensor implementation for electron-phonon data.
This class provides efficient storage and access to tensor data that is only defined for specific combinations of band, k-point, and spin indices.
Parameters
- band_kpoint_spin_index:
array_like - Index mapping for (band, kpoint, spin) combinations.
- band_start:
int - Starting band index for valid data.
- tensor:
array_like - The actual tensor data values in compressed form.
valid_bands
range
Return the range of valid band indices.
Returns
range- Range object representing the valid band indices.