Changelog

Added

Add qiskit_nature.mappers.second_quantization.BravyiKitaevSuperFastMapper implementing
the Bravyi-Kitaev super-fast fermion-to-qubit mapping. For example
```
from qiskit_nature.mappers.second_quantization import BravyiKitaevSuperFastMapper
mapper = BravyiKitaevSuperFastMapper()
mapper.map(fermionic_op)
```
The qiskit_nature.operators.SecondQuantizedOp now has a method
qiskit_nature.operators.SecondQuantizedOp.is_hermitian() method which will
return True if the operator is equivalent to its adjoint and False otherwise
qiskit_nature.operators.SecondQuantizedOp.to_list() is now an abstract method of
qiskit_nature.operators.SecondQuantizedOp that is implemented by all subclasses
Add qiskit_nature.operators.second_quantization.FermionicOp.to_normal_order().
It returns the normal ordered fermionic operator that is equivalent to self.
Introduces the qiskit_nature.drivers.second_quantization.ElectronicStructureMoleculeDriver and
qiskit_nature.drivers.second_quantization.VibrationalStructureMoleculeDriver
that allow for the creation of Molecule-based drivers by specifying a molecule plus basis and
method (for Electronic Structure drivers only) and a driver type. An additional type AUTO allows for
the lookup of the first driver installed that supports the given method. The documentation of
those two molecule driver classes gives more details on it.
The Property framework is the new modular and extensible approach for
representing observable quantities. The framework is used as a replacement
for the legacy driver results like QMolecule and WatsonHamiltonian.
Please refer to the tutorial and documentation for more details.
Related Github issues:
- #148
- #167
- #220
- #243
- #263
- #264
- #303
Introduce the qiskit_nature.runtime.VQEProgram to allow leveraging Qiskit
Runtime to speed up the VQE algorithm. The qiskit_nature.runtime.VQEProgram
implements the qiskit.algorithms.MinimumEigensolver interface and can thus
be used as a drop-in replacement for other minimum eigensolvers like
qiskit.algorithms.VQE. See the tutorials under docs/tutorials for an
explicit example usage.
The internal data in qiskit_nature.operators.second_quantization.FermionicOp
have been changed. As a result, more data type is now accepted by initialize.
The ascending order constraint and the no-same index constraint have been removed.
In addition, the dense and sparse labels are now automatically detected by the existence of
underscores.

The property display_format of qiskit_nature.operators.second_quantization.FermionicOp
is added. There are two modes dense and sparse.
This display format can be switched by the property FermionicOp.display_format.
The internal API of the abstract class
qiskit_nature.operators.second_quantization.SecondQuantizedOp abstract class has been
changed to use qiskit.opflow.mixins.StarAlgebraMixin.

Changed

The qiskit_nature.circuit.library.EvolvedOperatorAnsatz is deprecated.
Use qiskit.circuit.library.EvolvedOperatorAnsatz as a direct replacement instead.
The property dagger in the second quantized operators is deprecated. Use adjoint() method
alternatively.
- the legacy driver return types, QMolecule and WatsonHamiltonian
- the legacy transformers acting on the now deprecated driver return types
- the BaseProblem.molecule_data and BaseProblem.molecule_data_transformed attributes
All currently existing drivers have been moved from qiskit_nature.drivers
to qiskit_nature.drivers.second_quantization. This is necessary because
future additions to Nature which reside in parallel to the
second_quantization submodules will not be using these drivers. Making
this separation reflects that in the code structure.
The same change was necessary for the existing qiskit_nature.transformers.

Fixed

Fixed an issue where qiskit_nature.operators.FermionicOp raises
unwanted ValueError when initialized with some list of sparse label.
Fixes the issue #198 where total dipole moment was not calculated correctly in the
ElectronicStructureResult.
QiskitNatureErrors where not being raised properly by the ActiveSpaceTransformer due to
ill-formatted error messages.
Fix qiskit_nature.algorithms.AdaptVQE after the update of
qiskit.algorithms.VQE which deleted the internal _energy_evaluation
method that Adapt-VQE was relying on.
The FreezeCoreTransformer (and ActiveSpaceTransformer) were incompatible with the automatic
Z2Symmetry reduction. This issue was fixed by correcting the
ElectronicStructureProblem.symmetry_sector_locator method.
The two-qubit reduction needs to be skipped when a qubit operator only has 2
(or even fewer) qubits.
The qiskit_nature.runtime.VQEProgram does support the evaluation of auxiliary
operators at the final state, but the
qiskit_nature.runtime.VQEProgram.supports_aux_operators method previously returned
False instead of True.
Allow Qiskit's qiskit.algorithms.optimizers.Optimizer classes as input for
the optimizer in the qiskit_nature.runtime.VQEProgram instead of only
dictionaries.
Changed documentation and code to better reflect rebranding of Qiskit's
chemistry module as Qiskit Nature.

Assets 2

29 Jul 20:32

manoelmarques

0.1.5

d11245f

Qiskit Nature 0.1.5

Changelog

Fixed

Allow Optimizers as input to VQEProgram (#290)

Assets 2

12 Jul 20:30

manoelmarques

0.1.4

db87b4c

Qiskit Nature 0.1.4

[Stable] Prepare 0.1.4 release (#265)

* Prepare 0.1.4 release

* Deprecated Location: Improve Windows compatibility (pathlib) for psi4 (#266)

* Update AdaptVQE to new, stateless VQE (#222)

* fix AdaptVQE

which previously used the (now deleted) internal method _evaluate_energy of the VQE

* add reno

Co-authored-by: Steve Wood <[email protected]>

* Bump Terra min. requirement

Co-authored-by: Julien Gacon <[email protected]>
Co-authored-by: Steve Wood <[email protected]>

Assets 2