--- title: Qiskit Fermions API documentation (latest version) description: Index of all the modules in the latest version of qiskit-fermions. source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit-fermions --- # qiskit-fermions Python API reference This is the reference for the Python API of the `qiskit-fermions` package. ## Operators - [Operator Representations](/docs/api/qiskit-fermions/operators) - [Operator Library](/docs/api/qiskit-fermions/operators-library) - [Operator Terms](/docs/api/qiskit-fermions/operators-terms) ## Mappers - [Representation Mappers](/docs/api/qiskit-fermions/mappers) - [Mapper Library](/docs/api/qiskit-fermions/mappers-library) - [Mapper Optimizations](/docs/api/qiskit-fermions/mappers-optimization) ## Circuits - [Circuit Representation](/docs/api/qiskit-fermions/circuit) - [Circuit Library](/docs/api/qiskit-fermions/circuit-library) ## Transpiler - [Transpiler](/docs/api/qiskit-fermions/transpiler) - [Transpiler Passes](/docs/api/qiskit-fermions/transpiler-passes) - [Transpiler Pass Plugins](/docs/api/qiskit-fermions/transpiler-passes-plugins) - [Transpiler Pass Utilities](/docs/api/qiskit-fermions/transpiler-passes-utils) - [Transpiler Presets](/docs/api/qiskit-fermions/transpiler-presets) ## Linear Algebra - [Linear Algebra Utilities](/docs/api/qiskit-fermions/linalg) ## Protocols - [Protocols](/docs/api/qiskit-fermions/protocols) ## Utilities - [Optional Dependencies](/docs/api/qiskit-fermions/utils-optionals) ## Contents - [API index](/docs/api/qiskit-fermions) - [Release notes](/docs/api/qiskit-fermions/release-notes) - qiskit_fermions.circuit - [Module overview](/docs/api/qiskit-fermions/circuit) - [FermionicCircuit](/docs/api/qiskit-fermions/circuit-fermionic-circuit) - [FermionicDAGCircuit](/docs/api/qiskit-fermions/circuit-fermionic-dag-circuit) - [FermionicGate](/docs/api/qiskit-fermions/circuit-fermionic-gate) - [FermionicMode](/docs/api/qiskit-fermions/circuit-fermionic-mode) - [FermionicRegister](/docs/api/qiskit-fermions/circuit-fermionic-register) - [FermionicSpecifier](/docs/api/qiskit-fermions/circuit-fermionic-specifier) - qiskit_fermions.circuit.library - [Module overview](/docs/api/qiskit-fermions/circuit-library) - [Evolution](/docs/api/qiskit-fermions/circuit-library-evolution) - [InitializeModes](/docs/api/qiskit-fermions/circuit-library-initialize-modes) - [OrbitalRotation](/docs/api/qiskit-fermions/circuit-library-orbital-rotation) - [PrepareSlaterDeterminant](/docs/api/qiskit-fermions/circuit-library-prepare-slater-determinant) - [UCC](/docs/api/qiskit-fermions/circuit-library-ucc) - [UCJ](/docs/api/qiskit-fermions/circuit-library-ucj) - qiskit_fermions.linalg - [Module overview](/docs/api/qiskit-fermions/linalg) - [apply_unitary](/docs/api/qiskit-fermions/linalg-apply-unitary) - [double_factorized_2body](/docs/api/qiskit-fermions/linalg-double-factorized-2-body) - [double_factorized_t2](/docs/api/qiskit-fermions/linalg-double-factorized-t-2) - [double_factorized_t2_alpha_beta](/docs/api/qiskit-fermions/linalg-double-factorized-t-2-alpha-beta) - [givens_decomposition](/docs/api/qiskit-fermions/linalg-givens-decomposition) - [givens_decomposition_slater](/docs/api/qiskit-fermions/linalg-givens-decomposition-slater) - [linear_operator](/docs/api/qiskit-fermions/linalg-linear-operator) - [reconstruct_t2](/docs/api/qiskit-fermions/linalg-reconstruct-t-2) - [reconstruct_t2_alpha_beta](/docs/api/qiskit-fermions/linalg-reconstruct-t-2-alpha-beta) - qiskit_fermions.mappers - [Module overview](/docs/api/qiskit-fermions/mappers) - [map_edge_vertex_generators](/docs/api/qiskit-fermions/mappers-map-edge-vertex-generators) - [map_fermion_action_generators](/docs/api/qiskit-fermions/mappers-map-fermion-action-generators) - [map_majorana_action_generators](/docs/api/qiskit-fermions/mappers-map-majorana-action-generators) - [map_transfer_vertex_generators](/docs/api/qiskit-fermions/mappers-map-transfer-vertex-generators) - qiskit_fermions.mappers.library - [Module overview](/docs/api/qiskit-fermions/mappers-library) - [edge_vertex_to_fermion](/docs/api/qiskit-fermions/mappers-library-edge-vertex-to-fermion) - [edge_vertex_to_majorana](/docs/api/qiskit-fermions/mappers-library-edge-vertex-to-majorana) - [fermion_jordan_wigner](/docs/api/qiskit-fermions/mappers-library-fermion-jordan-wigner) - [fermion_operator](/docs/api/qiskit-fermions/mappers-library-fermion-operator) - [fermion_to_majorana](/docs/api/qiskit-fermions/mappers-library-fermion-to-majorana) - [jordan_wigner](/docs/api/qiskit-fermions/mappers-library-jordan-wigner) - [majorana_operator](/docs/api/qiskit-fermions/mappers-library-majorana-operator) - [majorana_to_fermion](/docs/api/qiskit-fermions/mappers-library-majorana-to-fermion) - [transfer_vertex_to_edge_vertex](/docs/api/qiskit-fermions/mappers-library-transfer-vertex-to-edge-vertex) - [transfer_vertex_to_fermion](/docs/api/qiskit-fermions/mappers-library-transfer-vertex-to-fermion) - [transfer_vertex_to_majorana](/docs/api/qiskit-fermions/mappers-library-transfer-vertex-to-majorana) - qiskit_fermions.mappers.optimization - [Module overview](/docs/api/qiskit-fermions/mappers-optimization) - [build_excitation_span_minimization_model](/docs/api/qiskit-fermions/mappers-optimization-build-excitation-span-minimization-model) - qiskit_fermions.operators - [Module overview](/docs/api/qiskit-fermions/operators) - [ann](/docs/api/qiskit-fermions/operators-ann) - [cre](/docs/api/qiskit-fermions/operators-cre) - [EdgeAction](/docs/api/qiskit-fermions/operators-edge-action-edge-action) - [EdgeVertexOperator](/docs/api/qiskit-fermions/operators-edge-vertex-operator) - [FermionAction](/docs/api/qiskit-fermions/operators-fermion-action-fermion-action) - [FermionOperator](/docs/api/qiskit-fermions/operators-fermion-operator) - [gamma](/docs/api/qiskit-fermions/operators-gamma) - [MajoranaAction](/docs/api/qiskit-fermions/operators-majorana-action-majorana-action) - [MajoranaOperator](/docs/api/qiskit-fermions/operators-majorana-operator) - [OperatorTrait](/docs/api/qiskit-fermions/operators-operator-trait) - [TransferAction](/docs/api/qiskit-fermions/operators-transfer-action-transfer-action) - [TransferVertexOperator](/docs/api/qiskit-fermions/operators-transfer-vertex-operator) - qiskit_fermions.operators.library - [Module overview](/docs/api/qiskit-fermions/operators-library) - [anti_commutator](/docs/api/qiskit-fermions/operators-library-anti-commutator) - [commutator](/docs/api/qiskit-fermions/operators-library-commutator) - [double_commutator](/docs/api/qiskit-fermions/operators-library-double-commutator) - [FCIDump](/docs/api/qiskit-fermions/operators-library-fci-dump) - qiskit_fermions.operators.terms - [Module overview](/docs/api/qiskit-fermions/operators-terms) - [canonical_order](/docs/api/qiskit-fermions/operators-terms-canonical-order) - [filter_diagonal_terms](/docs/api/qiskit-fermions/operators-terms-filter-diagonal-terms) - [group_terms_by_electronic_structure](/docs/api/qiskit-fermions/operators-terms-group-terms-by-electronic-structure) - [order_terms](/docs/api/qiskit-fermions/operators-terms-order-terms) - qiskit_fermions.protocols - [Module overview](/docs/api/qiskit-fermions/protocols) - [SupportsApplyUnitary](/docs/api/qiskit-fermions/protocols-supports-apply-unitary) - [SupportsApplyUnitaryPlaced](/docs/api/qiskit-fermions/protocols-supports-apply-unitary-placed) - [SupportsCommutators](/docs/api/qiskit-fermions/protocols-supports-commutators) - [SupportsFermionOperator](/docs/api/qiskit-fermions/protocols-supports-fermion-operator) - [SupportsLinearOperator](/docs/api/qiskit-fermions/protocols-supports-linear-operator) - [SupportsMajoranaOperator](/docs/api/qiskit-fermions/protocols-supports-majorana-operator) - qiskit_fermions.transpiler - [Module overview](/docs/api/qiskit-fermions/transpiler) - [F2QLayout](/docs/api/qiskit-fermions/transpiler-f-2-q-layout) - [FermionicCircuitToDAG](/docs/api/qiskit-fermions/transpiler-fermionic-circuit-to-dag) - [FermionicDAGToCircuit](/docs/api/qiskit-fermions/transpiler-fermionic-dag-to-circuit) - [FermionicPassManager](/docs/api/qiskit-fermions/transpiler-fermionic-pass-manager) - [QuantumDAGToCircuit](/docs/api/qiskit-fermions/transpiler-quantum-dag-to-circuit) - qiskit_fermions.transpiler.passes - [Module overview](/docs/api/qiskit-fermions/transpiler-passes) - [CustomF2QLayout](/docs/api/qiskit-fermions/transpiler-passes-custom-f-2-q-layout) - [F2QSynthesis](/docs/api/qiskit-fermions/transpiler-passes-f-2-q-synthesis) - [F2QSynthesisConfig](/docs/api/qiskit-fermions/transpiler-passes-synthesis-synthesis-f-2-q-synthesis-config) - [F2QSynthesisPlugin](/docs/api/qiskit-fermions/transpiler-passes-synthesis-f-2-q-synthesis-plugin) - [F2QSynthesisPluginManager](/docs/api/qiskit-fermions/transpiler-passes-synthesis-f-2-q-synthesis-plugin-manager) - [GivensDecompositionOrbitalRotationSynthesis](/docs/api/qiskit-fermions/transpiler-passes-synthesis-givens-decomposition-orbital-rotation-synthesis) - [GivensDecompositionSlaterDeterminantSynthesis](/docs/api/qiskit-fermions/transpiler-passes-synthesis-givens-decomposition-slater-determinant-synthesis) - [MapperFnEvolutionSynthesis](/docs/api/qiskit-fermions/transpiler-passes-synthesis-mapper-fn-evolution-synthesis) - [MergeOrbitalRotations](/docs/api/qiskit-fermions/transpiler-passes-merge-orbital-rotations) - [MergeSlaterDeterminantPreparation](/docs/api/qiskit-fermions/transpiler-passes-merge-slater-determinant-preparation) - [QDriftTrotterization](/docs/api/qiskit-fermions/transpiler-passes-q-drift-trotterization) - [RelabelModes](/docs/api/qiskit-fermions/transpiler-passes-relabel-modes) - [TrivialF2QLayout](/docs/api/qiskit-fermions/transpiler-passes-trivial-f-2-q-layout) - [TrivialOccupationInitializeModesSynthesis](/docs/api/qiskit-fermions/transpiler-passes-synthesis-trivial-occupation-initialize-modes-synthesis) - qiskit_fermions.transpiler.passes.utils - [Module overview](/docs/api/qiskit-fermions/transpiler-passes-utils) - [map_node_single_register](/docs/api/qiskit-fermions/transpiler-passes-utils-map-node-single-register) - qiskit_fermions.transpiler.presets - [Module overview](/docs/api/qiskit-fermions/transpiler-presets) - [generate_preset_jw_pass_manager](/docs/api/qiskit-fermions/transpiler-presets-generate-preset-jw-pass-manager) - [qiskit_fermions.utils.optionals](/docs/api/qiskit-fermions/utils-optionals) - [Transpiler Pass Plugins](/docs/api/qiskit-fermions/transpiler-passes-plugins)