Engineering Papers⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 3017147

Nuclear Responses with Neural-Network Quantum States

Parnes, Elad [The Hebrew University, Jerusalem (Israel)] (ORCID:0009000343070340)·Barnea, Nir [The Hebrew University, Jerusalem (Israel)] (ORCID:0000000180363052)·Carleo, Giuseppe [École Polytechnique Fédérale de Lausanne (EPFL) (Switzerland)] (ORCID:0000000288874356)·Lovato, Alessandro [Argonne National Laboratory (ANL), Argonne, IL (United States); INFN-TIFPA Trento Institute for Fundamental Physics and Applications (Italy)] (ORCID:0000000221944954)·Rocco, Noemi [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); CSIC—Universitat de València (Spain)] (ORCID:0000000271507322)·Zhang, Xilin [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000192785359)
View original source ↗Read source document ↗Export metadata ↓

Abstract

We introduce a variational Monte Carlo framework that combines neural-network quantum states with the Lorentz integral transform technique to compute the dynamical properties of self-bound quantum many-body systems in continuous Hilbert spaces. While broadly applicable to various quantum systems, including atoms and molecules, in this initial application we focus on the photoabsorption cross section of light nuclei, where benchmarks against numerically exact techniques are available. Our accurate theoretical predictions are complemented by robust uncertainty quantification, enabling meaningful comparisons with experiments. Here, we demonstrate that a relatively simple nuclear Hamiltonian—based on a leading-order pionless EFT expansion and known to accurately reproduce ground-state energies of nuclei with 𝐴 ≤ 40—also provides a reliable description of the photoabsorption cross section.

Explore related subjects

Ab initio calculationsFew-body systemsLepton induced nuclear reactionsMonte Carlo methodsNuclear many-body theoryNuclear reactionsPhotonuclear reactionsQuantum Monte Carlo

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Parnes, Elad [The Hebrew University, Jerusalem (Israel)] (ORCID:0009000343070340), Barnea, Nir [The Hebrew University, Jerusalem (Israel)] (ORCID:0000000180363052), Carleo, Giuseppe [École Polytechnique Fédérale de Lausanne (EPFL) (Switzerland)] (ORCID:0000000288874356), Lovato, Alessandro [Argonne National Laboratory (ANL), Argonne, IL (United States); INFN-TIFPA Trento Institute for Fundamental Physics and Applications (Italy)] (ORCID:0000000221944954), Rocco, Noemi [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); CSIC—Universitat de València (Spain)] (ORCID:0000000271507322), Zhang, Xilin [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000192785359). 2026-01-23. Nuclear Responses with Neural-Network Quantum States. https://doi.org/10.1103/tlqz-nw28

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

Pressure-induced 𝐵⁢1 to 𝐵⁢2 phase transition in CeN studied by 𝑎⁢𝑏 𝑖⁢𝑛⁢𝑖⁢𝑡⁢𝑖⁢𝑜 correlation matrix renormalization theory calculations

We apply correlation matrix renormalization theory (CMRT) to cerium nitride (CeN) under pressure. For 𝐵⁢1 (NaCl-type) phase, CMRT gives an equation of state consistent with ambient pressure experiments. It produces electronic density-of-state (DOS) characterized by a sharp 4⁢𝑓 quasiparticle resonance peak pinned at the Fermi level and two subbands formed by strong hybridization between the localized Ce-4⁢𝑓 electrons and the itinerant Ce-5⁢𝑑 and N-2⁢𝑝 electrons below the Fermi level, consistent with x-ray photoemission spectroscopy experiments. Upon compression, CMRT predicts a first-order 𝐵⁢1 → 𝐵⁢2 (CsCl-type) transition with ∼11% volume collapse in agreement with experiments. Across the transition, the 4⁢𝑓 spectrum broadens, the 4⁢𝑓 orbital occupancy increases, and the hybridization with conduction states enhances, signaling a crossover from partially localized to more itinerant 4⁢𝑓 behavior. Furthermore, these features are in excellent agreement with experimental observations, demonstrating that CMRT provides a parameter-free description and prediction of correlation-driven structural and electronic transitions in rare-earth compounds.

Ab initio calculations↗
DOE OSTI2026

Theoretical and kinetic modeling study of hydrazine oxidation

The present work constitutes the first theoretical and kinetic modeling study of hydrazine oxidation, which may be important for burnout in ammonia-fueled combustion. The kinetics of the oxidation of N 2 H 4 , N 2 H 3 and tHNNH by molecular oxygen were investigated via a quantum chemistry/canonical transition state theory approach. Geometries and anharmonic frequencies were obtained with density functional theory, and energies from coupled cluster calculations (CCSD(T)) extrapolated to the infinite basis set limit, with corrections for core-valence electron correlation, scalar relativistic effects, and higher level correlation up to lambda coupled cluster, CCSDT(Q) Λ . The key reactions occurred on the N 2 H 4 O 2 potential energy surface, where the results indicated a fast reaction of N 2 H 3 with HO 2 via singlet adducts to yield tHNNH + H 2 O 2 and HNN(H)O + H 2 O, while reaction on the triplet surface proceeds via a bound complex followed by a tight, submerged barrier to yield N 2 H 4 + O 2 . The results were incorporated in a detailed reaction mechanism, which was used to interpret the shock tube results from Michel and Wagner (1965) on the effect of O 2 on hydrazine conversion at 1100–1400 K. The kinetic model captured qualitatively the observed behavior, but underestimated the reaction rate under oxidizing conditions. The hydrazine pyrolysis chemistry dominated conversion at reducing conditions and/or high temperature. At oxidizing conditions and intermediate temperatures (≲ 1400 K), reactions of N 2 -amines with HO 2 and O 2 were important for the oxidation rate.

Ab initio calculations↗
DOE OSTI2026

Computing nuclear response functions with time-dependent coupled-cluster theory

We compute nuclear response functions by solving the time-dependent 𝐴-body Schrödinger equation, recording the time-dependent transition moment and extracting spectral information via Fourier transforms. The solution of the time-dependent many-body problem accounts for correlations on top of the mean field by taking advantage of a time-dependent formulation of coupled-cluster theory. As a validation, we focus on electric dipole transitions in 4 He and 16 O and compare moments of the response function distribution to the results of an equivalent static framework, finding negligible discrepancies. We investigate how proton and neutron densities evolve in time, and we see the traditional picture of soft and giant dipole resonances as collective oscillations of protons and neutrons emerging from our calculations in 16 O and 24 O. Furthermore, this method also allows us to investigate the behavior of the nucleus in the presence of a strong electric field. In that regime, the behavior of the system becomes chaotic. Qualitatively, the spectral information obtained in this limit is in line with previous time-dependent mean-field results.

Ab initio calculations↗