09-Nature Tutorial- Properties-or-OperatorFactories

#This code is at:
#https://qiskit-community.github.io/qiskit-nature/tutorials/09_properties.html

from qiskit_nature.second_q.problems import BaseProblem

dummy_hamiltonian = None

base_problem = BaseProblem(dummy_hamiltonian)
print(base_problem.properties)

<qiskit_nature.second_q.problems.properties_container.PropertiesContainer object at 0x73421fae5450>

from qiskit_nature.second_q.properties import AngularMomentum

print("AngularMomentum is in problem.properties:", AngularMomentum in base_problem.properties)

print("Adding AngularMomentum to problem.properties...")
base_problem.properties.add(AngularMomentum(2))

print("AngularMomentum is in problem.properties:", AngularMomentum in base_problem.properties)

print("Discarding AngularMomentum from problem.properties...")
base_problem.properties.discard(AngularMomentum)

print("AngularMomentum is in problem.properties:", AngularMomentum in base_problem.properties)

AngularMomentum is in problem.properties: False
Adding AngularMomentum to problem.properties...
AngularMomentum is in problem.properties: True
Discarding AngularMomentum from problem.properties...
AngularMomentum is in problem.properties: False

from qiskit_nature.second_q.drivers import PySCFDriver

es_problem = PySCFDriver().run()

print(es_problem.properties.particle_number)
print(es_problem.properties.angular_momentum)
print(es_problem.properties.magnetization)
print(es_problem.properties.electronic_dipole_moment)
print(es_problem.properties.electronic_density)

<qiskit_nature.second_q.properties.particle_number.ParticleNumber object at 0x73421fadda50>
<qiskit_nature.second_q.properties.angular_momentum.AngularMomentum object at 0x73421b16f0d0>
<qiskit_nature.second_q.properties.magnetization.Magnetization object at 0x73421ab68fd0>
<qiskit_nature.second_q.properties.dipole_moment.ElectronicDipoleMoment object at 0x734234b47550>
None

from qiskit_nature.second_q.properties import ElectronicDensity

density = ElectronicDensity.from_orbital_occupation(
    es_problem.orbital_occupations,
    es_problem.orbital_occupations_b,
)

es_problem.properties.electronic_density = density