QMolecule Transformers (qiskit_nature.transformers)

Transformers act on a QMolecule to produce an altered copy of it as per the specific transformer. So for instance the FreezeCoreTransformer will alter the integrals and number of particles in a way that freezes the core orbitals, storing an extracted energy in the QMolecule to compensate for this that would need to be included back into any ground state energy computation to get complete result.


The interface for implementing methods which map from one QMolecule or ‘WatsonHamiltonian’ to another.

ActiveSpaceTransformer([num_electrons, …])

The Active-Space reduction.

FreezeCoreTransformer([freeze_core, …])

The Freeze-Core reduction.