qat.fermion.chemistry.wrapper.MoleculeInfo
- class qat.fermion.chemistry.wrapper.MoleculeInfo(hamiltonian: MolecularHamiltonian, n_electrons: int, noons: ndarray | List[float], orbital_energies: ndarray)
MoleculeInfo helper class. This class is a even higher level version of the
MolecularHamiltonian
.- Parameters:
hamiltonian (MolecularHamiltonian) – The MolecularHamiltonian of the studied molecule.
n_electrons (int) – Number of electrons.
noons (Union[np.ndarray, List[float]]) – Natural orbital occupation number.
orbital_energies (np.ndarray) – Orbital energies.
- nqbits
The total number of qubits.
- Type:
int
- one_body_integrals
One-body integrals \(I_{uv}\).
- Type:
np.ndarray
- two_body_integrals
Two-body integrals \(I_{uvwx}\).
- Type:
np.ndarray
- constant_coeff
Constant coefficient \(r\) (core repulsion).
- Type:
np.ndarray
- hamiltonian
The
MolecularHamiltonian
of the studied molecule.- Type:
- n_electrons
Number of electrons.
- Type:
int
- noons
Natural orbital occupation number.
- Type:
Union[np.ndarray, List[float]]
- orbital_energies
Orbital energies.
- Type:
np.ndarray
Example
import numpy as np from qat.fermion.chemistry import MolecularHamiltonian, MoleculeInfo # For illustration purpose, initialize random one- and two-body integrals, and a constant one_body_integral = np.random.randn(2, 2) two_body_integral = np.random.randn(2, 2, 2, 2) constant = np.random.rand() noons = list(np.random.randn(10)) orbital_energies = list(np.random.randn(10)) # Define the MolecularHamiltonian mol_h = MolecularHamiltonian(one_body_integral, two_body_integral, constant) # Define MoleculeInfo molecule = MoleculeInfo( mol_h, n_electrons=4, noons=noons, orbital_energies=orbital_energies ) print(molecule)
MoleculeInfo( - MolecularHamiltonian( * constant_coeff : 0.26725887019998384 * integrals shape ** one_body_integrals : (2, 2) ** two_body_integrals : (2, 2, 2, 2) ) - n_electrons = 4 - noons = [np.float64(-1.801389230256094), np.float64(0.6458353410390759), np.float64(1.423064352400823), np.float64(-0.26530443130961817), np.float64(-0.20731968364452644), np.float64(-2.191071722271951), np.float64(-0.5907010829689321), np.float64(-0.7974142473029893), np.float64(-0.21843531743747005), np.float64(-0.7625921038737118)] - orbital energies = [np.float64(-0.9166051529417562), np.float64(-0.4367762379595715), np.float64(2.177441547004653), np.float64(1.1381330820181599), np.float64(-0.8006060622682302), np.float64(0.1369866371970403), np.float64(0.8467054482961067), np.float64(0.6885074953939484), np.float64(0.5377585227832), np.float64(0.2719878350171553)] )
- restrict_active_space(threshold_1: float | None = 0.02, threshold_2: float | None = 0.001)
Same method as the
MolecularHamiltonian
methodselect_active_space()
, except it also modifies all the molecule parameters accordingly (NOONs, orbital energies, and number of electrons).For more information, see
select_active_space()
documentation.- Parameters:
threshold_1 (Optional[float]) – The upper threshold \(\varepsilon_1\) on the NOON of an active orbital.
threshold_2 (Optional[float]) – The lower threshold \(\varepsilon_2\) on the NOON of an active orbital.