tequila.quantumchemistry.QuantumChemistryPsi4.make_upccgsd_ansatz

QuantumChemistryPsi4.make_upccgsd_ansatz(include_singles: bool = True, include_reference: bool = True, indices: list = None, label: str = None, order: int = 1, *args, **kwargs)

UpGCCSD Ansatz similar as described by Lee et. al.

Parameters

• include_singles – include singles excitations

• include_reference – include the HF reference state as initial state

• indices – pass custom defined set of indices from which the ansatz will be created List of tuples of tuples spin-indices e.g. [((2*p,2*q),(2*p+1,2*q+1)), …]

• label – An additional label that is set with the variables default is None and no label will be set: variables names will be (x, (p,q)) for x in range(order) with a label the variables will be named (label, (x, (p,q)))

• order – Order of the ansatz (default is 1) determines how often the ordering gets repeated parameters of repeating layers are independent

Returns

Return type

UpGCCSD ansatz