qiskit.chemistry.components.variational_forms.UCCSD¶
-
class
UCCSD(num_orbitals, num_particles, reps=1, active_occupied=None, active_unoccupied=None, initial_state=None, qubit_mapping='parity', two_qubit_reduction=True, num_time_slices=1, shallow_circuit_concat=True, z2_symmetries=None, method_singles='both', method_doubles='ucc', excitation_type='sd', same_spin_doubles=True, skip_commute_test=False)[Quellcode]¶ This trial wavefunction is a Unitary Coupled-Cluster Single and Double excitations variational form. For more information, see https://arxiv.org/abs/1805.04340 And for the singlet q-UCCD (full) and pair q-UCCD) see: https://arxiv.org/abs/1911.10864
Constructor.
- Parameter
num_orbitals (
int) – number of spin orbitals, has a min. value of 1.num_particles (
Union[List[int],int]) – number of particles, if it is a list, the first number is alpha and the second number if beta.reps (
int) – number of repetitions of basic module, has a min. value of 1.active_occupied (
Optional[List[int]]) – list of occupied orbitals to consider as active space.active_unoccupied (
Optional[List[int]]) – list of unoccupied orbitals to consider as active space.initial_state (
Optional[InitialState]) – An initial state object.qubit_mapping (
str) – qubit mapping type.two_qubit_reduction (
bool) – two qubit reduction is applied or not.num_time_slices (
int) – parameters for dynamics, has a min. value of 1.shallow_circuit_concat (
bool) – indicate whether to use shallow (cheap) mode for circuit concatenation.z2_symmetries (
Optional[Z2Symmetries]) – represent the Z2 symmetries, including symmetries, sq_paulis, sq_list, tapering_values, and cliffords.method_singles (
str) – specify the single excitation considered. ‚alpha‘, ‚beta‘, ‚both‘ only alpha or beta spin-orbital single excitations or both (all of them).method_doubles (
str) – specify the single excitation considered. ‚ucc‘ (conventional ucc), succ (singlet ucc), succ_full (singlet ucc full), pucc (pair ucc).excitation_type (
str) – specify the excitation type ‚sd‘, ‚s‘, ‚d‘ respectively for single and double, only single, only double excitations.same_spin_doubles (
bool) – enable double excitations of the same spin.skip_commute_test (
bool) –- when tapering excitation operators we test and exclude any that do
not commute with symmetries. This test can be skipped to include all tapered excitation operators whether they commute or not.
- Raises:
ValueError: Num particles list is not 2 entries
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__init__(num_orbitals, num_particles, reps=1, active_occupied=None, active_unoccupied=None, initial_state=None, qubit_mapping='parity', two_qubit_reduction=True, num_time_slices=1, shallow_circuit_concat=True, z2_symmetries=None, method_singles='both', method_doubles='ucc', excitation_type='sd', same_spin_doubles=True, skip_commute_test=False)[Quellcode]¶ Constructor.
- Parameter
num_orbitals (
int) – number of spin orbitals, has a min. value of 1.num_particles (
Union[List[int],int]) – number of particles, if it is a list, the first number is alpha and the second number if beta.reps (
int) – number of repetitions of basic module, has a min. value of 1.active_occupied (
Optional[List[int]]) – list of occupied orbitals to consider as active space.active_unoccupied (
Optional[List[int]]) – list of unoccupied orbitals to consider as active space.initial_state (
Optional[InitialState]) – An initial state object.qubit_mapping (
str) – qubit mapping type.two_qubit_reduction (
bool) – two qubit reduction is applied or not.num_time_slices (
int) – parameters for dynamics, has a min. value of 1.shallow_circuit_concat (
bool) – indicate whether to use shallow (cheap) mode for circuit concatenation.z2_symmetries (
Optional[Z2Symmetries]) – represent the Z2 symmetries, including symmetries, sq_paulis, sq_list, tapering_values, and cliffords.method_singles (
str) – specify the single excitation considered. ‚alpha‘, ‚beta‘, ‚both‘ only alpha or beta spin-orbital single excitations or both (all of them).method_doubles (
str) – specify the single excitation considered. ‚ucc‘ (conventional ucc), succ (singlet ucc), succ_full (singlet ucc full), pucc (pair ucc).excitation_type (
str) – specify the excitation type ‚sd‘, ‚s‘, ‚d‘ respectively for single and double, only single, only double excitations.same_spin_doubles (
bool) – enable double excitations of the same spin.skip_commute_test (
bool) –- when tapering excitation operators we test and exclude any that do
not commute with symmetries. This test can be skipped to include all tapered excitation operators whether they commute or not.
- Raises:
ValueError: Num particles list is not 2 entries
Methods
__init__(num_orbitals, num_particles[, …])Constructor.
compute_excitation_lists(num_particles, …)Computes single and double excitation lists.
compute_excitation_lists_singlet(double_exc, …)Outputs the list of lists of grouped excitation.
construct_circuit(parameters[, q])Construct the variational form, given its parameters.
get_entangler_map(map_type, num_qubits[, offset])returns entangler map
group_excitations(list_de, num_orbitals)Groups the excitations and gives out the remaining ones in the list_de_temp list because those excitations are controlled by the same parameter in full singlet UCCSD unlike in usual UCCSD where every excitation has its own parameter.
group_excitations_if_same_ao(list_de, …)Define that, given list of double excitations list_de and number of spin-orbitals num_orbitals, which excitations involve the same spatial orbitals for full singlet UCCSD.
Triggers the adaptive behavior of this UCCSD instance.
order_labels_for_hopping_ops(double_exc, gde)Orders the hopping operators according to the grouped excitations for the full singlet UCCSD.
Pops the hopping operator that was added last.
push_hopping_operator(excitation)Pushes a new hopping operator.
same_ao_double_excitation_block_spin(de_1, …)Regroups the excitations that involve same spatial orbitals for example, with labeling.
validate_entangler_map(entangler_map, num_qubits)validate entangler map
Attributes
Getter of double excitation list :returns: double excitation list :rtype: list[list[int]]
Returns the full list of available excitations (called the pool).
Number of parameters of the variational form.
Number of qubits of the variational form.
Parameter bounds.
Getter of preferred initial points based on the given initial state.
Getter of single excitation list :returns: single excitation list :rtype: list[list[int]]
Whether or not the sub-class support parameterized circuit.
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static
compute_excitation_lists(num_particles, num_orbitals, active_occ_list=None, active_unocc_list=None, same_spin_doubles=True, method_singles='both', method_doubles='ucc', excitation_type='sd')[Quellcode]¶ Computes single and double excitation lists.
- Parameter
num_particles (Union(list, int)) – number of particles, if it is a tuple, the first number is alpha and the second number if beta.
num_orbitals (int) – Total number of spin orbitals
active_occ_list (list) – List of occupied orbitals to include, indices are 0 to n where n is max(num_alpha, num_beta)
active_unocc_list (list) – List of unoccupied orbitals to include, indices are 0 to m where m is num_orbitals // 2 - min(num_alpha, num_beta)
same_spin_doubles (bool) – True to include alpha,alpha and beta,beta double excitations as well as alpha,beta pairings. False includes only alpha,beta
excitation_type (str) – choose ‚sd‘, ‚s‘, ‚d‘ to compute q-UCCSD, q-UCCS, q-UCCD excitation lists
method_singles (str) – specify type of single excitations, ‚alpha‘, ‚beta‘, ‚both‘ only alpha or beta spin-orbital single excitations or both (all single excitations)
method_doubles (str) – choose method for double excitations ‚ucc‘ (conventional ucc), ‚succ‘ (singlet ucc), ‚succ_full‘ (singlet ucc full), ‚pucc‘ (pair ucc)
- Rückgabe
Single excitation list list: Double excitation list
- Rückgabetyp
list
- Verursacht
ValueError – invalid setting of number of particles
ValueError – invalid setting of number of orbitals
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static
compute_excitation_lists_singlet(double_exc, num_orbitals)[Quellcode]¶ Outputs the list of lists of grouped excitation. A single list inside is controlled by the same parameter theta.
- Parameter
double_exc (list) – exc.group. [[0,1,2,3], […]]
num_orbitals (int) – number of molecular orbitals
- Rückgabe
de_groups grouped excitations
- Rückgabetyp
list
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construct_circuit(parameters, q=None)[Quellcode]¶ Construct the variational form, given its parameters.
- Parameter
parameters (Union(numpy.ndarray, list[Parameter], ParameterVector)) – circuit parameters
q (QuantumRegister, optional) – Quantum Register for the circuit.
- Rückgabe
a quantum circuit with given parameters
- Rückgabetyp
- Verursacht
ValueError – the number of parameters is incorrect.
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property
double_excitations¶ Getter of double excitation list :returns: double excitation list :rtype: list[list[int]]
-
property
excitation_pool¶ Returns the full list of available excitations (called the pool).
- Rückgabetyp
List[WeightedPauliOperator]
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static
get_entangler_map(map_type, num_qubits, offset=0)¶ returns entangler map
-
static
group_excitations(list_de, num_orbitals)[Quellcode]¶ Groups the excitations and gives out the remaining ones in the list_de_temp list because those excitations are controlled by the same parameter in full singlet UCCSD unlike in usual UCCSD where every excitation has its own parameter.
- Parameter
list_de (list) – list of the double excitations grouped
num_orbitals (int) – number of spin-orbitals (qubits)
- Rückgabe
list_same_ao_group, list_de_temp, the grouped double_exc (that involve same spatial orbitals)
- Rückgabetyp
tuple
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static
group_excitations_if_same_ao(list_de, num_orbitals)[Quellcode]¶ Define that, given list of double excitations list_de and number of spin-orbitals num_orbitals, which excitations involve the same spatial orbitals for full singlet UCCSD.
- Parameter
list_de (list) – list of double exc
num_orbitals (int) – number of spin-orbitals
- Rückgabe
grouped list of excitations
- Rückgabetyp
list
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manage_hopping_operators()[Quellcode]¶ Triggers the adaptive behavior of this UCCSD instance. This function is used by the Adaptive VQE algorithm. It stores the full list of available hopping operators in a so called „excitation pool“ and clears the previous list to be empty. Furthermore, the depth is asserted to be 1 which is required by the Adaptive VQE algorithm.
-
property
num_parameters¶ Number of parameters of the variational form.
- Rückgabe
An integer indicating the number of parameters.
- Rückgabetyp
int
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property
num_qubits¶ Number of qubits of the variational form.
- Rückgabe
An integer indicating the number of qubits.
- Rückgabetyp
int
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static
order_labels_for_hopping_ops(double_exc, gde)[Quellcode]¶ Orders the hopping operators according to the grouped excitations for the full singlet UCCSD.
- Parameter
double_exc (list) – list of double excitations
gde (list of lists) – list of grouped excitations for full singlet UCCSD
- Rückgabe
ordered_labels to order hopping ops
- Rückgabetyp
list
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property
parameter_bounds¶ Parameter bounds.
- Rückgabe
A list of pairs indicating the bounds, as (lower, upper). None indicates an unbounded parameter in the corresponding direction. If None is returned, problem is fully unbounded.
- Rückgabetyp
list
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pop_hopping_operator()[Quellcode]¶ Pops the hopping operator that was added last.
-
property
preferred_init_points¶ Getter of preferred initial points based on the given initial state.
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push_hopping_operator(excitation)[Quellcode]¶ Pushes a new hopping operator.
- Parameter
excitation (WeightedPauliOperator) – the new hopping operator to be added
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static
same_ao_double_excitation_block_spin(de_1, de_2, num_orbitals)[Quellcode]¶ Regroups the excitations that involve same spatial orbitals for example, with labeling.
2— —5 1— —4 0-o- -o-3
excitations [0,1,3,5] and [0,2,3,4] are controlled by the same parameter in the full singlet UCCSD unlike in usual UCCSD where every excitation is controlled by independent parameter.
- Parameter
de_1 (list) – double exc in block spin [ from to from to ]
de_2 (list) – double exc in block spin [ from to from to ]
num_orbitals (int) – number of molecular orbitals
- Rückgabe
says if given excitation involves same spatial orbitals 1 = yes, 0 = no.
- Rückgabetyp
int
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property
setting¶
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property
single_excitations¶ Getter of single excitation list :returns: single excitation list :rtype: list[list[int]]
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property
support_parameterized_circuit¶ Whether or not the sub-class support parameterized circuit.
- Rückgabe
indicate the sub-class support parameterized circuit
- Rückgabetyp
boolean
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static
validate_entangler_map(entangler_map, num_qubits)¶ validate entangler map