notes/Machine Tips (Quantum)/Resources/Algorithms/Alg Collection/How many qubits do I need?.md

via Xanadu.ai's pennylane software.

How many qubits/gates do I need to run this algorithm?

module for estimating through process of first and second quantization:

# first quantization 

>>> n = 100000        # number of plane waves
>>> eta = 156         # number of electrons
>>> omega = 1145.166  # unit cell volume in atomic units
>>> algo = FirstQuantization(n, eta, omega)
>>> algo.gates
1.10e+13
>>> algo.qubits
4416

# second quantization with double factored Hamiltonian 
# Hamiltonia 

symbols  = ['O', 'H', 'H']
geometry = np.array([[0.00000000,  0.00000000,  0.28377432],
                    [0.00000000,  1.45278171, -1.00662237],
                    [0.00000000, -1.45278171, -1.00662237]], requires_grad = False)

mol = qml.qchem.Molecule(symbols, geometry, basis_name='sto-3g')
core, one, two = qml.qchem.electron_integrals(mol)()

algo = DoubleFactorization(one, two)

and voila!

>>> print(algo.gates, algo.qubits)
103969925, 290

and even more capabilities are available the more you explore! :)