qrisp.operators.fermionic.FermionicOperator.from_pyscf#

classmethod FermionicOperator.from_pyscf(pyscf_molecular_data)[source]#

Loads the data of a PySCF molecule into a FermionicOperator.

Parameters:

pyscf_molecular_datapyscf.gto.mole.Mole: The molecule to load.

Returns:

molecule_hamiltonianFermionicOperator: The molecule as an operator.

Examples

We load the Hydrogen molecule and perform a hamiltonian simulation:

>>> from pyscf import gto
>>> mol = gto.M(atom = '''H 0 0 0; H 0 0 0.74''', basis = 'sto-3g')
>>> H = FermionicOperator.from_pyscf(mol)
>>> print(H)
-0.181210462015197*a0*a1*c2*c3 + 0.181210462015197*a0*c1*c2*a3 
- 1.25330978664598*c0*a0 + 0.674755926814448*c0*a0*c1*a1 
+ 0.482500939335616*c0*a0*c2*a2 + 0.663711401350814*c0*a0*c3*a3 
+ 0.181210462015197*c0*a1*a2*c3 - 0.181210462015197*c0*c1*a2*a3
- 1.25330978664598*c1*a1 + 0.663711401350814*c1*a1*c2*a2 
+ 0.482500939335616*c1*a1*c3*a3 - 0.475068848772178*c2*a2 
+ 0.697651504490463*c2*a2*c3*a3 - 0.475068848772178*c3*a3

Create a QuantumVariable and initialize two electrons in the upper orbitals.

>>> from qrisp import QuantumVariable
>>> electron_state = QuantumVariable(4)
>>> electron_state[:] = "0011"

Simulate for \(t = 100\) Angstrom seconds.

>>> U = H.trotterization()
>>> U(electron_state, t = 100, steps = 20)
>>> print(electron_state)
{'0011': 0.75331, '1100': 0.24669}

We see that the electrons decayed to one of the lower levels. How cool is that?!