A Remarkable Application of Zassenhaus Formula to Strongly Correlated Electron Systems
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AbstractWe show that the Zassenhaus decomposition for the exponential of the sum of two non-commuting operators, simplifies drastically when these operators satisfy a simple condition, called the no-mixed adjoint property. An important application to a Unitary Coupled Cluster method for strongly correlated electron systems is presented. This ansatz requires no Trotterization and is exact on a quantum computer with a finite number of Givens gate equals to the number of free parameters. The formulas obtained in this work also shed light on why and when optimization after Trotterization gives exact solutions in disentangled forms of unitary coupled cluster.Featured image: Givens gate circuits for LiH in a minimal basis setPopular summaryWe show that the Trotter-Suzuki approximation can be completely avoided thanks to the Zassenhaus formula in the 2D-Block pair Unitary Coupled Cluster” (2D-BpUCC) ansatz for Quantum Chemistry, so that the latter can be exactly prepared on a quantum computer. The underlying mathematical property of this result has broad potential applications across a diverse spectrum of quantum algorithms, extending well beyond quantum chemistry.► BibTeX data@article{Jourdan2026remarkable, doi = {10.22331/q-2026-04-08-2057}, url = {https://doi.org/10.22331/q-2026-04-08-2057}, title = {A {R}emarkable {A}pplication of {Z}assenhaus {F}ormula to {S}trongly {C}orrelated {E}lectron {S}ystems}, author = {Jourdan, Louis and Cassam-Chena{\"{i}}, Patrick}, journal = {{Quantum}}, issn = {2521-327X}, publisher = {{Verein zur F{\"{o}}rderung des Open Access Publizierens in den Quantenwissenschaften}}, volume = {10}, pages = {2057}, month = apr, year = {2026} }► References [1] F. Casas, A. Escorihuela-Tomàs and P. A. Moreno Casares. "Approximating exponentials of commutators by optimized product formulas". Quantum Inf. Process. 24, 47 (2025). url: https://doi.org/10.1007/s11128-025-04659-z. https://doi.org/10.1007/s11128-025-04659-z [2] W. Magnus. "On the Exponential Solution of Differential Equations for a Linear Operator". Comm. Pure App. Math. 7, 649-673 (1954). url: https://doi.org/10.1002/cpa.3160070404. https://doi.org/10.1002/cpa.3160070404 [3] R. M. Wilcox. "Exponential Operators and Parameter Differentiation in Quantum Physics". J. Math. Phys. 8, 962-982 (1967). url: https://doi.org/10.1063/1.1705306. https://doi.org/10.1063/1.1705306 [4] R. M. Suzuki. "On the Convergence of Exponential Operators - the Zassenhaus Formula, BCH Formula and Systematic Approximants". Commun. Math. Phys. 57, 193-200 (1977). url: https://doi.org/10.1007/bf01614161. https://doi.org/10.1007/bf01614161 [5] D. Scholz and M. Weyrauch. "A note on the Zassenhaus product formula". J. Math. Phys. 47, 033505 (2006). url: https://doi.org/10.1063/1.2178586. https://doi.org/10.1063/1.2178586 [6] F. Casas, A. Murua and M. Nadinic. "Efficient computation of the Zassenhaus formula". Comput. Phys. Commun. 183, 2386-2391 (2012). url: https://doi.org/10.1016/j.cpc.2012.06.006. https://doi.org/10.1016/j.cpc.2012.06.006 [7] L. Wang, Y. Gao and N. Jing. "On multi-variable Zassenhaus formula". Front. Math. China 14, 421-433 (2019). url: https://doi.org/10.1007/s11464-019-0760-1. https://doi.org/10.1007/s11464-019-0760-1 [8] F. Fer. "Résolution de l’équation matricielle $\frac{dU}{dt} = p{U}$ par produit infini d’exponentielles matricielles". Bulletin de la Classe des sciences 44, 818-829 (1958). url: https://doi.org/10.3406/barb.1958.68918. https://doi.org/10.3406/barb.1958.68918 [9] A. Arnal, F. Casas,C. Chiralt and J. A. Oteo. "A Unifying Framework for Perturbative Exponential Factorizations". Mathematics 9, 637 (2021). url: https://doi.org/10.3390/math9060637. https://doi.org/10.3390/math9060637 [10] K. Ebrahimi-Fard and F. Patras. "A Zassenhaus-Type Algorithm Solves The Bogoliubov Recursion". Bulg. J. Phys. 35, 303-315 (2008). url: https://doi.org/10.48550/arXiv.0710.5134. https://doi.org/10.48550/arXiv.0710.5134 [11] H. F. Trotter. "On the Product of Semi-Groups of Operators". Proc. Am. Math. Soc. 10, 545-551 (1959). url: https://doi.org/10.1090/s0002-9939-1959-0108732-6. https://doi.org/10.1090/s0002-9939-1959-0108732-6 [12] P. Jayakumar, T. Zeng and A. F. Izmaylov. "On the Feasibility of Exact Unitary Transformations for Many-body Hamiltonians". (2025). url: arXiv:2510.10957. https://doi.org/10.48550/arXiv.2510.10957 arXiv:2510.10957 [13] V. Kurlin. "The Baker-Campbell-Hausdorff Formula in the Free Metabelian Lie Algebra". J. of Lie Theory 17, 525-538 (2007). url: https://doi.org/10.48550/arXiv.math/0606330. https://doi.org/10.48550/arXiv.math/0606330 [14] J. Preskill. "Quantum Computing in the NISQ era and beyond". Quantum 2, 79 (2018). url: https://doi.org/10.22331/q-2018-08-06-79. https://doi.org/10.22331/q-2018-08-06-79 [15] M. Bauer, R. Chetrite, K. Ebrahimi-Fard, F. Patras. "Time-Ordering and a Generalized Magnus Expansion". Lett. Math. Phys. 103, 331-350 (2013). url: https://doi.org/10.1007/s11005-012-0596-z. https://doi.org/10.1007/s11005-012-0596-z [16] R. J. Bartlett and M. Musial. "Coupled-cluster theory in quantum chemistry". Rev. Mod. Phys. 79, 291 (2007). url: https://doi.org/10.1103/RevModPhys.79.291. https://doi.org/10.1103/RevModPhys.79.291 [17] A. Laestadius and F. M. Faulstich. "The coupled-cluster formalism - a mathematical perspective". Molecular Physics 117, 2362-2373 (2019). url: https://doi.org/10.1080/00268976.2018.1564848. https://doi.org/10.1080/00268976.2018.1564848 [18] A. Leszczyk, M. Máté, O. Legeza and K. Boguslawski. "Assessing the Accuracy of Tailored Coupled Cluster Methods Corrected by Electronic Wave Functions of Polynomial Cost". J. Chem. Theory Comput. 18.1, 96-117 (2022). url: https://doi.org/10.1021/acs.jctc.1c00284. https://doi.org/10.1021/acs.jctc.1c00284 [19] P. Tecmer and K. Boguslawski. "Geminal-based electronic structure methods in quantum chemistry. Toward a geminal model chemistry". Phys. Chem. Chem. Phys. 24, 23026-23048 (2022). url: https://doi.org/10.1039/D2CP02528K. https://doi.org/10.1039/D2CP02528K [20] A. Peruzzo, J. McClean, P. Shadbolt, M.-H. Yung, X.-Q. Zhou, P. J. Love, A. Aspuru-Guzik and J. L. O’Brien. "A Variational eigenvalue solver on a photonic quantum processor". Nature Comm. 5, 4213 (2014). url: https://doi.org/10.1038/ncomms5213. https://doi.org/10.1038/ncomms5213 [21] M.-H. Yung, J. Casanova, A. Mezzacapo, J. McClean, L. Lamata, A. Aspuru-Guzik and E. Solano. "From transistor to trapped-ion computers for quantum chemistry". Sci. Rep. 4, 3589 (2014). url: https://doi.org/10.1038/srep03589. https://doi.org/10.1038/srep03589 [22] J. R. McClean, J. Romero, R. Babbush and A. Aspuru-Guzik. "The theory of variational hybrid quantum-classical algorithms". New J. Phys. 18, 023023 (2016). url: https://doi.org/10.1088/1367-2630/18/2/023023. https://doi.org/10.1088/1367-2630/18/2/023023 [23] J. Romero, R. Babbush, J. R. McClean, C. Hempel, P. J. Love and A. Aspuru-Guzik. "Strategies for quantum computing molecular energies using the unitary coupled cluster ansatz". Quantum Sci. Technol. 4, 014008 (2019). url: https://doi.org/10.1088/2058-9565/aad3e4. https://doi.org/10.1088/2058-9565/aad3e4 [24] H. R. Grimsley, S. E. Economou, E. Barnes and N. J. Mayhall. "An adaptive variational algorithm for exact molecular simulations on a quantum computer". Nat. Commun. 10, 3007 (2019). url: https://doi.org/10.1038/s41467-019-10988-2. https://doi.org/10.1038/s41467-019-10988-2 [25] J. Lee, W. J. Huggins, M. Head-Gordon, K. B. Whaley. "Generalized Unitary Coupled Cluster Wavefunctions for Quantum Computation". J. Theor. Comp. Chem. 15.1, 311-324 (2019). url: https://doi.org/10.1021/acs.jctc.8b01004. https://doi.org/10.1021/acs.jctc.8b01004 [26] I. O. Sokolov, M. Pistoia, P. J. Ollitrault, D. Greenberg, J. Rice, P. Kl. Barkoutsos and I. Tavernelli. "Quantum orbital-optimized unitary coupled cluster methods in the strongly correlated regime: Can quantum algorithms outperform their classical equivalents ?". J. Chem. Phys. 152, 124107 (2020). url: https://doi.org/10.1063/1.5141835. https://doi.org/10.1063/1.5141835 [27] W. J. Huggins, J. Lee, U. Baek, B. O’Gorman and K. B. Whaley. "A non-orthogonal variational quantum eigensolver". New J. Phys. 22, 073009 (2020). url: https://doi.org/10.1088/1367-2630/ab867b. https://doi.org/10.1088/1367-2630/ab867b [28] I. G. Ryabinkin, R. A. Lang, S. N. Genin and A. F. Izmaylov. "Iterative Qubit Coupled Cluster approach with efficient screening of generators". J. Chem. Theory Comput. 16.2, 1055-1063 (2020). url: https://doi.org/10.1021/acs.jctc.9b01084. https://doi.org/10.1021/acs.jctc.9b01084 [29] Q.-X. Xie, W.-G. Zhang, X.-S. Xu, S. Liu and Y. Zhao. "Qubit unitary coupled cluster with generalized single and paired double excitations ansatz for variational quantum eigensolver". Int. J. Quantum Chem. 122, e27001 (2022). url: https://doi.org/10.1002/qua.27001. https://doi.org/10.1002/qua.27001 [30] P. Cassam-Chenaï and L. Jourdan. "2D-Block Geminals: guidelines to choose effective excitations". J. Chem. Phys. 163, 174111 (2025). url: https://doi.org/10.1063/5.0296682. https://doi.org/10.1063/5.0296682 [31] W. A. Goddard III. "Improved Quantum Theory of Many-Electron Systems. II.
The Basic Method". Phys. Rev. 157, 81 (1967). url: https://doi.org/10.1103/PhysRev.157.81. https://doi.org/10.1103/PhysRev.157.81 [32] W. A. Goddard III, T. H. Dunning, W. J. Hunt and P. J. Hay. "Generalized Valence Bond Description of Bonding in Low-Lying States of Molecules". Acc. Chem. Res. 6.11, 368-376 (1973). url: https://doi.org/10.1021/ar50071a002. https://doi.org/10.1021/ar50071a002 [33] Q. Wang, M. Duan, E. Xu, J. Zou and S. Li. "Describing Strong Correlation with Block-Correlated Coupled Cluster Theory". J. Phys. Chem. Lett. 11.18, 7536-7543 (2020). url: https://doi.org/10.1021/acs.jpclett.0c02117. https://doi.org/10.1021/acs.jpclett.0c02117 [34] J. M. Arrazola, O. Di Matteo, N. Quesada, S. Jahangiri, A. Delgado and N. Killoran. "Universal quantum circuits for quantum chemistry". Quantum 6, 742 (2022). url: https://doi.org/10.22331/q-2022-06-20-742. https://doi.org/10.22331/q-2022-06-20-742 [35] A. Khamoshi, F. A. Evangelista and G. E Scuseria. "Correlating AGP on a quantum computer". Quantum Sci. Technol. 6, 014004 (2020). url: https://doi.org/10.1088/2058-9565/abc1bb. https://doi.org/10.1088/2058-9565/abc1bb [36] V. E. Elfving, M. Millaruelo, J. A. Gámez and C. Gogolin. "Simulating quantum chemistry in the seniority-zero space on qubit-based quantum computers". Phys. Rev. A 103, 032605 (2021). url: https://doi.org/10.1103/PhysRevA.103.032605. https://doi.org/10.1103/PhysRevA.103.032605 [37] F. A. Evangelista, G. K. Chan and G. E. Scuseria. "Exact parameterization of fermionic wave functions via unitary coupled cluster theory". J. Chem. Phys. 151, 244112 (2019). url: https://doi.org/10.1063/1.5133059. https://doi.org/10.1063/1.5133059Cited byCould not fetch Crossref cited-by data during last attempt 2026-04-08 12:45:57: Could not fetch cited-by data for 10.22331/q-2026-04-08-2057 from Crossref. This is normal if the DOI was registered recently. Could not fetch ADS cited-by data during last attempt 2026-04-08 12:45:58: No response from ADS or unable to decode the received json data when getting the list of citing works.This Paper is published in Quantum under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. Copyright remains with the original copyright holders such as the authors or their institutions. AbstractWe show that the Zassenhaus decomposition for the exponential of the sum of two non-commuting operators, simplifies drastically when these operators satisfy a simple condition, called the no-mixed adjoint property. An important application to a Unitary Coupled Cluster method for strongly correlated electron systems is presented. This ansatz requires no Trotterization and is exact on a quantum computer with a finite number of Givens gate equals to the number of free parameters. The formulas obtained in this work also shed light on why and when optimization after Trotterization gives exact solutions in disentangled forms of unitary coupled cluster.Featured image: Givens gate circuits for LiH in a minimal basis setPopular summaryWe show that the Trotter-Suzuki approximation can be completely avoided thanks to the Zassenhaus formula in the 2D-Block pair Unitary Coupled Cluster” (2D-BpUCC) ansatz for Quantum Chemistry, so that the latter can be exactly prepared on a quantum computer. The underlying mathematical property of this result has broad potential applications across a diverse spectrum of quantum algorithms, extending well beyond quantum chemistry.► BibTeX data@article{Jourdan2026remarkable, doi = {10.22331/q-2026-04-08-2057}, url = {https://doi.org/10.22331/q-2026-04-08-2057}, title = {A {R}emarkable {A}pplication of {Z}assenhaus {F}ormula to {S}trongly {C}orrelated {E}lectron {S}ystems}, author = {Jourdan, Louis and Cassam-Chena{\"{i}}, Patrick}, journal = {{Quantum}}, issn = {2521-327X}, publisher = {{Verein zur F{\"{o}}rderung des Open Access Publizierens in den Quantenwissenschaften}}, volume = {10}, pages = {2057}, month = apr, year = {2026} }► References [1] F. Casas, A. Escorihuela-Tomàs and P. A. Moreno Casares. "Approximating exponentials of commutators by optimized product formulas". Quantum Inf. Process. 24, 47 (2025). url: https://doi.org/10.1007/s11128-025-04659-z. https://doi.org/10.1007/s11128-025-04659-z [2] W. Magnus. "On the Exponential Solution of Differential Equations for a Linear Operator". Comm. Pure App. Math. 7, 649-673 (1954). url: https://doi.org/10.1002/cpa.3160070404. https://doi.org/10.1002/cpa.3160070404 [3] R. M. Wilcox. "Exponential Operators and Parameter Differentiation in Quantum Physics". J. Math. Phys. 8, 962-982 (1967). url: https://doi.org/10.1063/1.1705306. https://doi.org/10.1063/1.1705306 [4] R. M. Suzuki. "On the Convergence of Exponential Operators - the Zassenhaus Formula, BCH Formula and Systematic Approximants". Commun. Math. Phys. 57, 193-200 (1977). url: https://doi.org/10.1007/bf01614161. https://doi.org/10.1007/bf01614161 [5] D. Scholz and M. Weyrauch. "A note on the Zassenhaus product formula". J. Math. Phys. 47, 033505 (2006). url: https://doi.org/10.1063/1.2178586. https://doi.org/10.1063/1.2178586 [6] F. Casas, A. Murua and M. Nadinic. "Efficient computation of the Zassenhaus formula". Comput. Phys. Commun. 183, 2386-2391 (2012). url: https://doi.org/10.1016/j.cpc.2012.06.006. https://doi.org/10.1016/j.cpc.2012.06.006 [7] L. Wang, Y. Gao and N. Jing. "On multi-variable Zassenhaus formula". Front. Math. China 14, 421-433 (2019). url: https://doi.org/10.1007/s11464-019-0760-1. https://doi.org/10.1007/s11464-019-0760-1 [8] F. Fer. "Résolution de l’équation matricielle $\frac{dU}{dt} = p{U}$ par produit infini d’exponentielles matricielles". Bulletin de la Classe des sciences 44, 818-829 (1958). url: https://doi.org/10.3406/barb.1958.68918. https://doi.org/10.3406/barb.1958.68918 [9] A. Arnal, F. Casas,C. Chiralt and J. A. Oteo. "A Unifying Framework for Perturbative Exponential Factorizations". Mathematics 9, 637 (2021). url: https://doi.org/10.3390/math9060637. https://doi.org/10.3390/math9060637 [10] K. Ebrahimi-Fard and F. Patras. "A Zassenhaus-Type Algorithm Solves The Bogoliubov Recursion". Bulg. J. Phys. 35, 303-315 (2008). url: https://doi.org/10.48550/arXiv.0710.5134. https://doi.org/10.48550/arXiv.0710.5134 [11] H. F. Trotter. "On the Product of Semi-Groups of Operators". Proc. Am. Math. Soc. 10, 545-551 (1959). url: https://doi.org/10.1090/s0002-9939-1959-0108732-6. https://doi.org/10.1090/s0002-9939-1959-0108732-6 [12] P. Jayakumar, T. Zeng and A. F. Izmaylov. "On the Feasibility of Exact Unitary Transformations for Many-body Hamiltonians". (2025). url: arXiv:2510.10957. https://doi.org/10.48550/arXiv.2510.10957 arXiv:2510.10957 [13] V. Kurlin. "The Baker-Campbell-Hausdorff Formula in the Free Metabelian Lie Algebra". J. of Lie Theory 17, 525-538 (2007). url: https://doi.org/10.48550/arXiv.math/0606330. https://doi.org/10.48550/arXiv.math/0606330 [14] J. Preskill. "Quantum Computing in the NISQ era and beyond". Quantum 2, 79 (2018). url: https://doi.org/10.22331/q-2018-08-06-79. https://doi.org/10.22331/q-2018-08-06-79 [15] M. Bauer, R. Chetrite, K. Ebrahimi-Fard, F. Patras. "Time-Ordering and a Generalized Magnus Expansion". Lett. Math. Phys. 103, 331-350 (2013). url: https://doi.org/10.1007/s11005-012-0596-z. https://doi.org/10.1007/s11005-012-0596-z [16] R. J. Bartlett and M. Musial. "Coupled-cluster theory in quantum chemistry". Rev. Mod. Phys. 79, 291 (2007). url: https://doi.org/10.1103/RevModPhys.79.291. https://doi.org/10.1103/RevModPhys.79.291 [17] A. Laestadius and F. M. Faulstich. "The coupled-cluster formalism - a mathematical perspective". Molecular Physics 117, 2362-2373 (2019). url: https://doi.org/10.1080/00268976.2018.1564848. https://doi.org/10.1080/00268976.2018.1564848 [18] A. Leszczyk, M. Máté, O. Legeza and K. Boguslawski. "Assessing the Accuracy of Tailored Coupled Cluster Methods Corrected by Electronic Wave Functions of Polynomial Cost". J. Chem. Theory Comput. 18.1, 96-117 (2022). url: https://doi.org/10.1021/acs.jctc.1c00284. https://doi.org/10.1021/acs.jctc.1c00284 [19] P. Tecmer and K. Boguslawski. "Geminal-based electronic structure methods in quantum chemistry. Toward a geminal model chemistry". Phys. Chem. Chem. Phys. 24, 23026-23048 (2022). url: https://doi.org/10.1039/D2CP02528K. https://doi.org/10.1039/D2CP02528K [20] A. Peruzzo, J. McClean, P. Shadbolt, M.-H. Yung, X.-Q. Zhou, P. J. Love, A. Aspuru-Guzik and J. L. O’Brien. "A Variational eigenvalue solver on a photonic quantum processor". Nature Comm. 5, 4213 (2014). url: https://doi.org/10.1038/ncomms5213. https://doi.org/10.1038/ncomms5213 [21] M.-H. Yung, J. Casanova, A. Mezzacapo, J. McClean, L. Lamata, A. Aspuru-Guzik and E. Solano. "From transistor to trapped-ion computers for quantum chemistry". Sci. Rep. 4, 3589 (2014). url: https://doi.org/10.1038/srep03589. https://doi.org/10.1038/srep03589 [22] J. R. McClean, J. Romero, R. Babbush and A. Aspuru-Guzik. "The theory of variational hybrid quantum-classical algorithms". New J. Phys. 18, 023023 (2016). url: https://doi.org/10.1088/1367-2630/18/2/023023. https://doi.org/10.1088/1367-2630/18/2/023023 [23] J. Romero, R. Babbush, J. R. McClean, C. Hempel, P. J. Love and A. Aspuru-Guzik. "Strategies for quantum computing molecular energies using the unitary coupled cluster ansatz". Quantum Sci. Technol. 4, 014008 (2019). url: https://doi.org/10.1088/2058-9565/aad3e4. https://doi.org/10.1088/2058-9565/aad3e4 [24] H. R. Grimsley, S. E. Economou, E. Barnes and N. J. Mayhall. "An adaptive variational algorithm for exact molecular simulations on a quantum computer". Nat. Commun. 10, 3007 (2019). url: https://doi.org/10.1038/s41467-019-10988-2. https://doi.org/10.1038/s41467-019-10988-2 [25] J. Lee, W. J. Huggins, M. Head-Gordon, K. B. Whaley. "Generalized Unitary Coupled Cluster Wavefunctions for Quantum Computation". J. Theor. Comp. Chem. 15.1, 311-324 (2019). url: https://doi.org/10.1021/acs.jctc.8b01004. https://doi.org/10.1021/acs.jctc.8b01004 [26] I. O. Sokolov, M. Pistoia, P. J. Ollitrault, D. Greenberg, J. Rice, P. Kl. Barkoutsos and I. Tavernelli. "Quantum orbital-optimized unitary coupled cluster methods in the strongly correlated regime: Can quantum algorithms outperform their classical equivalents ?". J. Chem. Phys. 152, 124107 (2020). url: https://doi.org/10.1063/1.5141835. https://doi.org/10.1063/1.5141835 [27] W. J. Huggins, J. Lee, U. Baek, B. O’Gorman and K. B. Whaley. "A non-orthogonal variational quantum eigensolver". New J. Phys. 22, 073009 (2020). url: https://doi.org/10.1088/1367-2630/ab867b. https://doi.org/10.1088/1367-2630/ab867b [28] I. G. Ryabinkin, R. A. Lang, S. N. Genin and A. F. Izmaylov. "Iterative Qubit Coupled Cluster approach with efficient screening of generators". J. Chem. Theory Comput. 16.2, 1055-1063 (2020). url: https://doi.org/10.1021/acs.jctc.9b01084. https://doi.org/10.1021/acs.jctc.9b01084 [29] Q.-X. Xie, W.-G. Zhang, X.-S. Xu, S. Liu and Y. Zhao. "Qubit unitary coupled cluster with generalized single and paired double excitations ansatz for variational quantum eigensolver". Int. J. Quantum Chem. 122, e27001 (2022). url: https://doi.org/10.1002/qua.27001. https://doi.org/10.1002/qua.27001 [30] P. Cassam-Chenaï and L. Jourdan. "2D-Block Geminals: guidelines to choose effective excitations". J. Chem. Phys. 163, 174111 (2025). url: https://doi.org/10.1063/5.0296682. https://doi.org/10.1063/5.0296682 [31] W. A. Goddard III. "Improved Quantum Theory of Many-Electron Systems. II.
The Basic Method". Phys. Rev. 157, 81 (1967). url: https://doi.org/10.1103/PhysRev.157.81. https://doi.org/10.1103/PhysRev.157.81 [32] W. A. Goddard III, T. H. Dunning, W. J. Hunt and P. J. Hay. "Generalized Valence Bond Description of Bonding in Low-Lying States of Molecules". Acc. Chem. Res. 6.11, 368-376 (1973). url: https://doi.org/10.1021/ar50071a002. https://doi.org/10.1021/ar50071a002 [33] Q. Wang, M. Duan, E. Xu, J. Zou and S. Li. "Describing Strong Correlation with Block-Correlated Coupled Cluster Theory". J. Phys. Chem. Lett. 11.18, 7536-7543 (2020). url: https://doi.org/10.1021/acs.jpclett.0c02117. https://doi.org/10.1021/acs.jpclett.0c02117 [34] J. M. Arrazola, O. Di Matteo, N. Quesada, S. Jahangiri, A. Delgado and N. Killoran. "Universal quantum circuits for quantum chemistry". Quantum 6, 742 (2022). url: https://doi.org/10.22331/q-2022-06-20-742. https://doi.org/10.22331/q-2022-06-20-742 [35] A. Khamoshi, F. A. Evangelista and G. E Scuseria. "Correlating AGP on a quantum computer". Quantum Sci. Technol. 6, 014004 (2020). url: https://doi.org/10.1088/2058-9565/abc1bb. https://doi.org/10.1088/2058-9565/abc1bb [36] V. E. Elfving, M. Millaruelo, J. A. Gámez and C. Gogolin. "Simulating quantum chemistry in the seniority-zero space on qubit-based quantum computers". Phys. Rev. A 103, 032605 (2021). url: https://doi.org/10.1103/PhysRevA.103.032605. https://doi.org/10.1103/PhysRevA.103.032605 [37] F. A. Evangelista, G. K. Chan and G. E. Scuseria. "Exact parameterization of fermionic wave functions via unitary coupled cluster theory". J. Chem. Phys. 151, 244112 (2019). url: https://doi.org/10.1063/1.5133059. https://doi.org/10.1063/1.5133059Cited byCould not fetch Crossref cited-by data during last attempt 2026-04-08 12:45:57: Could not fetch cited-by data for 10.22331/q-2026-04-08-2057 from Crossref. This is normal if the DOI was registered recently. Could not fetch ADS cited-by data during last attempt 2026-04-08 12:45:58: No response from ADS or unable to decode the received json data when getting the list of citing works.This Paper is published in Quantum under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. Copyright remains with the original copyright holders such as the authors or their institutions.