Computing the molecular ground state energy in a restricted active space using quantum annealing

• URL: http://arxiv.org/abs/2512.11757v1
• Date: Fri, 12 Dec 2025 18:08:07 GMT
• Title: Computing the molecular ground state energy in a restricted active space using quantum annealing
• Abstract summary: Calculating the molecular ground-state energy is a central challenge in computational chemistry.<n>Quantum computing offers a promising alternative by mapping molecular Hamiltonians by qubits.<n>Previous studies have shown that it is possible to formulate molecular ground state calculations as discrete optimization problems.
• Score: 0.6445605125467574
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Calculating the molecular ground-state energy is a central challenge in computational chemistry. Conventional methods such as the Complete Active Space Configuration Interaction scale exponentially with molecular size, limiting their applicability to large molecules. Quantum computing offers a promising alternative by mapping molecular Hamiltonians by qubits, enabling cheaper computational scaling. Previous studies have shown that it is possible to formulate molecular ground state calculations as discrete optimization problems, addressable by quantum annealing. However, these efforts have been limited by previous generations of hardware and suboptimal annealing techniques. Here, the $H_{2}O$ ground-state problem is mapped to an Ising Hamiltonian using the Xian-Bias-Kas (XBK) method. By taking advantage of enhanced qubit connectivity and shorter embedding chains, it is solved with a more than doubled probability of achieving Hartree-Fock-level solutions with respect to the most advanced predecessor. Advanced annealing strategies extend Hartree-Fock-level accuracy to significantly larger problem instances, enabling solutions that use nearly 2.5 times more physically embedded qubits than the largest cases previously reported and allowing to improve annealing results by two orders of magnitude, reaching an energy difference of 0.120~Hartree relative to Hartree-Fock. These results show tangible progress toward practical quantum annealing applications in NISQ era.

Related papers

• Fault tolerant computation of the static structure factor and finite size effects [43.936586633107396]
  We develop a quantum post-processing strategy for the leading two-body finite-size correction.<n>After one-body shell effects are reduced by twist averaging, the dominant residual error is controlled by long-wavelength density fluctuations.<n>We also introduce adaptive global and local binary search procedures for identifying the infrared fitting window used to reconstruct the two-body finite size error correction.
  arXiv  Detail & Related papers  (2026-06-26T05:31:08Z)
• Large-scale Efficient Molecule Geometry Optimization with Hybrid Quantum-Classical Computing [1.1463843149836523]
  Accurately and efficiently predicting the equilibrium geometries of large molecules remains a central challenge in quantum computational chemistry.<n>Two major obstacles hinder progress: the large number of qubits required and the prohibitive cost of conventional nested optimization.<n>We introduce a co-optimization framework that combines Density Matrix Embedding Theory (DMET) with Variational Quantum Eigensolver (VQE) to address these limitations.
  arXiv  Detail & Related papers  (2025-09-09T07:31:29Z)
• A Scalable Heuristic for Molecular Docking on Neutral-Atom Quantum Processors [0.0]
  We show how a novel divide-and-conquer algorithm can be used to solve large-scale docking problems.<n>Our work paves the way for tackling large-scale docking challenges on near-term quantum hardware.
  arXiv  Detail & Related papers  (2025-08-25T15:54:52Z)
• Efficient Hamiltonian Simulation: A Utility Scale Perspective for Covalent Inhibitor Reactivity Prediction [0.25111276334134786]
  Quantum computing applications in the noisy intermediate-scale quantum (NISQ) era require algorithms that can generate shallower circuits feasible for today's quantum systems.<n>This is particularly challenging for quantum chemistry applications due to the inherent complexity of molecular systems.<n>We demonstrate a systematic circuit reduction approach for scaling to larger active spaces, while maintaining sufficient accuracy for molecular reactivity predictions using the Quantum-Centric Data-Driven R&D framework.
  arXiv  Detail & Related papers  (2024-12-20T11:25:01Z)
• Neural Quantum States and Peaked Molecular Wave Functions: Curse or Blessing? [0.5530212768657544]
  We introduce a novel algorithm for autoregressive sampling without replacement of a procedure to calculate a computationally cheaper surrogate for the local energy. Our calculations require substantially less resources and exhibit more than order of magnitude speedup compared to the previous works.
  arXiv  Detail & Related papers  (2024-08-14T15:49:04Z)
• Iterative Qubit Coupled Cluster using only Clifford circuits [36.136619420474766]
  An ideal state preparation protocol can be characterized by being easily generated classically. We propose a method that meets these requirements by introducing a variant of the iterative qubit coupled cluster (iQCC) We demonstrate the algorithm's correctness in ground-state simulations and extend our study to complex systems like the titanium-based compound Ti(C5H5)(CH3)3 with a (20, 20) active space.
  arXiv  Detail & Related papers  (2022-11-18T20:31:10Z)
• QAOA-in-QAOA: solving large-scale MaxCut problems on small quantum machines [81.4597482536073]
  Quantum approximate optimization algorithms (QAOAs) utilize the power of quantum machines and inherit the spirit of adiabatic evolution. We propose QAOA-in-QAOA ($textQAOA2$) to solve arbitrary large-scale MaxCut problems using quantum machines. Our method can be seamlessly embedded into other advanced strategies to enhance the capability of QAOAs in large-scale optimization problems.
  arXiv  Detail & Related papers  (2022-05-24T03:49:10Z)
• Chemistry beyond the Hartree-Fock limit via quantum computed moments [0.0]
  We implement the quantum computed moments (QCM) approach for hydrogen chain molecular systems up to H$_6$. Results provide strong evidence for the error suppression capability of the QCM method, particularly when coupled with post-processing error mitigation. Greater emphasis on more efficient representations of the Hamiltonian and classical preprocessing steps may enable the solution of larger systems on near-term quantum processors.
  arXiv  Detail & Related papers  (2021-11-15T23:04:23Z)
• Computing molecular excited states on a D-Wave quantum annealer [52.5289706853773]
  We demonstrate the use of a D-Wave quantum annealer for the calculation of excited electronic states of molecular systems. These simulations play an important role in a number of areas, such as photovoltaics, semiconductor technology and nanoscience.
  arXiv  Detail & Related papers  (2021-07-01T01:02:17Z)
• Optimizing Electronic Structure Simulations on a Trapped-ion Quantum Computer using Problem Decomposition [41.760443413408915]
  We experimentally demonstrate an end-to-end pipeline that focuses on minimizing quantum resources while maintaining accuracy. Using density matrix embedding theory as a problem decomposition technique, and an ion-trap quantum computer, we simulate a ring of 10 hydrogen atoms without freezing any electrons. Our experimental results are an early demonstration of the potential for problem decomposition to accurately simulate large molecules on quantum hardware.
  arXiv  Detail & Related papers  (2021-02-14T01:47:52Z)
• Engineering analog quantum chemistry Hamiltonians using cold atoms in optical lattices [69.50862982117127]
  We benchmark the working conditions of the numerically analog simulator and find less demanding experimental setups. We also provide a deeper understanding of the errors of the simulation appearing due to discretization and finite size effects.
  arXiv  Detail & Related papers  (2020-11-28T11:23:06Z)
• Electronic structure with direct diagonalization on a D-Wave quantum annealer [62.997667081978825]
  This work implements the general Quantum Annealer Eigensolver (QAE) algorithm to solve the molecular electronic Hamiltonian eigenvalue-eigenvector problem on a D-Wave 2000Q quantum annealer. We demonstrate the use of D-Wave hardware for obtaining ground and electronically excited states across a variety of small molecular systems.
  arXiv  Detail & Related papers  (2020-09-02T22:46:47Z)
• Hartree-Fock on a superconducting qubit quantum computer [30.152226344347064]
  Here, we perform a series of quantum simulations of chemistry the largest of which involved a dozen qubits, 78 two-qubit gates, and 114 one-qubit gates. We model the binding energy of $rm H_6$, $rm H_8$, $rm H_10$ and $rm H_12$ chains as well as the isomerization of diazene. We also demonstrate error-mitigation strategies based on $N$-representability which dramatically improve the effective fidelity of our experiments.
  arXiv  Detail & Related papers  (2020-04-08T18:00:06Z)
• Simulation of Thermal Relaxation in Spin Chemistry Systems on a Quantum Computer Using Inherent Qubit Decoherence [53.20999552522241]
  We seek to take advantage of qubit decoherence as a resource in simulating the behavior of real world quantum systems. We present three methods for implementing the thermal relaxation. We find excellent agreement between our results, experimental data, and the theoretical prediction.
  arXiv  Detail & Related papers  (2020-01-03T11:48:11Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.