Ground State Interface: Minor cleanups (#1357)

* Expose NumPyMinimumEigensolverFactory one module below

This is inline with the other factories being exposed too.

* Fix deprecation warning paths

* Add spin restriction to default fermionic filter

* Rename test_mes_gsc_calculation to test_groundstate_eigensolver

* Remove deprecation warnings in Hamiltonian-Enums

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

Author: mrossinek

qiskit/chemistry/algorithms/ground_state_solvers/__init__.py

@@ -15,11 +15,15 @@
 from .ground_state_solver import GroundStateSolver
 from .adapt_vqe import AdaptVQE
 from .ground_state_eigensolver import GroundStateEigensolver
-from .minimum_eigensolver_factories import MinimumEigensolverFactory, VQEUCCSDFactory
+from .minimum_eigensolver_factories import (MinimumEigensolverFactory,
+                                            NumPyMinimumEigensolverFactory,
+                                            VQEUCCSDFactory)
+
 
 __all__ = ['GroundStateSolver',
            'AdaptVQE',
            'GroundStateEigensolver',
            'MinimumEigensolverFactory',
+           'NumPyMinimumEigensolverFactory',
            'VQEUCCSDFactory'
            ]

qiskit/chemistry/core/hamiltonian.py

@@ -33,22 +33,12 @@
 
 class TransformationType(Enum):
     """ Transformation Type enum """
-    warnings.warn('The chemistry.core.TransformationType class is deprecated as of Qiskit Aqua '
-                  '0.8.0 and will be removed no earlier than 3 months after the release date. '
-                  'Instead, the '
-                  'chemistry.qubit_transformatons.fermionic_transformation.TransformationType can '
-                  'be used.', DeprecationWarning, stacklevel=2)
     FULL = 'full'
     PARTICLE_HOLE = 'particle_hole'
 
 
 class QubitMappingType(Enum):
     """ QubitMappingType enum """
-    warnings.warn('The chemistry.core.QubitMappingType class is deprecated as of Qiskit Aqua '
-                  '0.8.0 and will be removed no earlier than 3 months after the release date. '
-                  'Instead, the '
-                  'chemistry.qubit_transformatons.fermionic_transformation.QubitMappingType can '
-                  'be used.', DeprecationWarning, stacklevel=2)
     JORDAN_WIGNER = 'jordan_wigner'
     PARITY = 'parity'
     BRAVYI_KITAEV = 'bravyi_kitaev'

qiskit/chemistry/transformations/fermionic_transformation.py

@@ -474,7 +474,10 @@ def get_default_filter_criterion(self) -> Optional[Callable[[Union[List, np.ndar
         def filter_criterion(self, eigenstate, eigenvalue, aux_values):
             # the first aux_value is the evaluated number of particles
             num_particles_aux = aux_values[0][0]
-            return np.isclose(sum(self.molecule_info['num_particles']), num_particles_aux)
+            # the second aux_value is the total angular momentum which (for singlets) should be zero
+            total_angular_momentum_aux = aux_values[1][0]
+            return np.isclose(sum(self.molecule_info['num_particles']), num_particles_aux) and \
+                np.isclose(0., total_angular_momentum_aux)
 
         return partial(filter_criterion, self)
 

test/chemistry/test_mes_gsc_calculation.py renamed to test/chemistry/test_groundstate_eigensolver.py

@@ -10,7 +10,7 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-""" Test MinimumEigensovler ground state calculation """
+""" Test GroundStateEigensolver """
 
 import unittest
 
@@ -27,8 +27,8 @@
     (VQEUCCSDFactory, NumPyMinimumEigensolverFactory)
 
 
-class TestMESGSCCalculation(QiskitChemistryTestCase):
-    """ Test MinimumEigensovler ground state calculation """
+class TestGroundStateEigensolver(QiskitChemistryTestCase):
+    """ Test GroundStateEigensolver """
 
     def setUp(self):
         super().setUp()
@@ -52,6 +52,13 @@ def test_npme(self):
         res = calc.solve(self.driver)
         self.assertAlmostEqual(res.energy, self.reference_energy, places=6)
 
+    def test_npme_with_default_filter(self):
+        """ Test NumPyMinimumEigensolver with default filter """
+        solver = NumPyMinimumEigensolverFactory(use_default_filter_criterion=True)
+        calc = GroundStateEigensolver(self.transformation, solver)
+        res = calc.solve(self.driver)
+        self.assertAlmostEqual(res.energy, self.reference_energy, places=6)
+
     def test_vqe_uccsd(self):
         """ Test VQE UCCSD case """
         solver = VQEUCCSDFactory(QuantumInstance(BasicAer.get_backend('statevector_simulator')))