biostudies-literatureBelaloui NEDirectorate-General for Scientific Research and Technological DevelopmentAfrican Academy of SciencesMinist?re de l'Enseignement Sup?rieur et de la Recherche Scientifique6777-6792https://www.ebi.ac.uk/biostudies/studies/S-EPMC12288014biostudies-literatureUnknown21(14)We investigate the variational quantum eigensolver (VQE) for estimating the ground-state energy of the BeH₂ molecule, emphasizing practical implementation and performance on current quantum hardware. Our research presents a comparative study of HEA and UCCSD ansätze on noiseless and noisy simulations and implements VQE on recent IBM quantum computer noise models and a real quantum computer, IBM Fez, providing a fully functional code employing Qiskit 1.2. Our experiments confirm UCCSD's reliability in ideal conditions, while the HEA demonstrates greater robustness to hardware noise, achieving chemical accuracy on state-vector simulation (SVS). The results reveal that achieving ground-state energy within chemical accuracy is feasible without error mitigation during VQE convergenceJournal of chemical theory and computationGround-State Energy Estimation on Current Quantum Hardware through the Variational Quantum Eigensolver: A Practical Study.PMC12288014DCI-PANAF/2020/420-028Benslama ABelaloui NEBernal Neira DEKhamadja ARTounsi ALouamri MMRouabah MTfalseGround-State Energy Estimation on Current Quantum Hardware through the Variational Quantum Eigensolver: A Practical Study.We investigate the variational quantum eigensolver (VQE) for estimating the ground-state energy of the BeH₂ molecule, emphasizing practical implementation and performance on current quantum hardware. Our research presents a comparative study of HEA and UCCSD ansätze on noiseless and noisy simulations and implements VQE on recent IBM quantum computer noise models and a real quantum computer, IBM Fez, providing a fully functional code employing Qiskit 1.2. Our experiments confirm UCCSD's reliability in ideal conditions, while the HEA demonstrates greater robustness to hardware noise, achieving chemical accuracy on state-vector simulation (SVS). The results reveal that achieving ground-state energy within chemical accuracy is feasible without error mitigation during VQE convergence2025-01-01T00:00:00Z2025 Jul2026-03-31T10:47:40.832Z2025-08-30T03:05:39.297ZS-EPMC122880144058186010.1021/acs.jctc.4c01657