nlread¶

Included in QATK.Core

nlread(filename, class_type=None, object_id=None, read_state=None)¶

Function for reading configurations and results from files. The following file types are supported: HDF5 (only from ATK 2017 and later), GPAW, ASE, XYZ, Python scripts (also from ATK 2008.10 and earlier), CAR and TRAJ (ASE trajectories).

Parameters:

filename (str) – The file that objects should be loaded from.
class_type (class) – Only load objects of this type (HDF5 and GPAW only).
object_id (str) – Only load objects that match object_id.

Returns:: A list of the objects loaded from the file.
Return type:: list

Note

Argument changes:

read_state: Deprecated since 2026.03

Usage Examples¶

Restore the self-consistent state of a previous calculation (to save the state, see the Usage Examples for the nlsave function).

# Read self-consistent calculations
molecule_configuration_list = nlread(
    'nh3_scf.hdf5',
    MoleculeConfiguration
)

# Choose the first configuration in the list
molecule_configuration = molecule_configuration_list[0]

nh3_read.py

Restore the object with object_id = 'id0' from the NetCDF file bandstructure.hdf5 (to save the state, consult the nlsave function).

molecular_energy_spectrum = nlread(filename='spectrum.nc', object_id='id0')

Restore all MolecularEnergySpectrum objects from the file spectrum.hdf5 and select the first object.

molecular_energy_spectrums = nlread(
    'spectrum.hdf5',
    MolecularEnergySpectrum
    )
molecular_energy_spectrum = molecular_energy_spectrums[0]

More details regarding file IO in QuantumATK can be found here.