qml.qchem.repulsion_tensor

repulsion_tensor(basis_functions)[source]

Return a function that computes the electron repulsion tensor for a given set of basis functions.

Parameters

basis_functions (list[BasisFunction]) – basis functions

Returns

function that computes the electron repulsion tensor

Return type

function

Example

>>> symbols  = ['H', 'H']
>>> geometry = np.array([[0.0, 0.0, 0.0], [0.0, 0.0, 1.0]], requires_grad = False)
>>> alpha = np.array([[3.42525091, 0.62391373, 0.1688554],
>>>                   [3.42525091, 0.62391373, 0.1688554]], requires_grad=True)
>>> mol = qml.qchem.Molecule(symbols, geometry, alpha=alpha)
>>> args = [alpha]
>>> repulsion_tensor(mol.basis_set)(*args)
array([[[[0.77460595, 0.56886144], [0.56886144, 0.65017747]],
        [[0.56886144, 0.45590152], [0.45590152, 0.56886144]]],
       [[[0.56886144, 0.45590152], [0.45590152, 0.56886144]],
        [[0.65017747, 0.56886144],[0.56886144, 0.77460595]]]])