Taylor-mode AD automates vibration Hamiltonians
Users supply one coordinate mapping; kinetic and potential operators follow, and vibrational energies converge.
physics.atm-clus
Atomic and Molecular Clusters
Atomic and molecular clusters, nanoparticles: geometric, electronic, optical, chemical, magnetic properties, shell structure, phase transitions, optical spectroscopy, mass spectrometry, photoelectron spectroscopy, ionization potential, electron affinity, interaction with intense light pulses, electron diffraction, light scattering, ab initio calculations, DFT theory, fragmentation, Coulomb explosion, hydrodynamic expansion.
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C60 fullerene crystals yield tuneable band gaps from 2 to 2.5 eV
Four polymorphs of the same molecule span direct and indirect band gaps with strong excitons for optoelectronic design.
· “C₆₀ building blocks with tuneable structures for tailored functionalities”
Cubic molecules imprint diffraction on attosecond time delays
Simulations show ±100-attosecond delay and advance patterns that survive orientational averaging and can be seen by pump-probe chronoscopy.
· “Diffraction patterns in attosecond photoionization time delay”
Two-body descriptors capture three-body water physics
Per-monomer energy sums reproduce water's structure and dynamics at force-field-level cost.
Cavity rewires how water shares vibrational energy
Quantum simulation of a 21-molecule water cluster shows strong coupling opens new energy pathways, even to remote OH bonds.
X-ray fields, not size or aggregation, set H3+ yields on silica
Measuring one number per particle—the surface field—predicts how much trihydrogen forms on silica dust.
· “X-ray Driven Trihydrogen Formation on Silica Nanosurfaces”
A single molecule passes a high-dimensional Bell test at 2.34
Measured decoherence still lets Yb(trensal) beat CHSH and CGLMP bounds, opening molecular magnets to qudit tests.
· “Molecular spin qudits to test generalized Bell inequalities”
Edge modes hit exactly zero energy at one critical chain size
Non-Hermitian gain and loss cancel finite-size splitting, producing a sharp impedance peak in a topolectrical circuit.
· “Topological Zero Modes in Non-Hermitian Topolectrical Systems: Size and Impedance Control”
Na+ shell stays unstable for 5-6.5 ps inside helium droplet
Full pump-probe simulation shows the shell is held together only by the surrounding helium, and detected clusters keep reshuffling atoms.
Quantum beats trace O2+ wave packets to the b4Σg− state
A 200-picosecond scan pins rotational coherences in O2+ and confirms 800-nm resonant coupling.
· “Rotational coherences in O₂^+ following strong-field ionization”
500x weaker second plateau in liquids traced to distant recombination
The missing high-order response in liquid harmonics comes from electrons rejoining at the second solvation shell.
· “Multi-plateau high-harmonic generation in liquids driven by off-site recombination”
Optimized laser and magnetic field boost MgF photon scattering sixfold
Three AOM-controlled frequencies plus a tilted magnetic field raise scattered photons for MgF laser cooling.
· “Optical cycling of MgF molecules within the hyperfine states in X(N=1) state”
Cheap ab initio data keeps CIA spectra good to 10%
Even low-level potential and dipole surfaces give ~10% collision-induced absorption at room temperature, and better when hot.
Qudit phase gates reduce to N-body spin couplings
Exact identity maps multi-controlled qudit gates onto spin-spin Hamiltonians, opening a route to hypergraph states.
Multi-task training lifts accuracy across five atomistic datasets
Per-dataset heads beat single-task baselines on 24M structures and scale to 1,920 GPUs
Two-acceptor transfer runs 5.8-fold faster when vibrations oppose
Model traces the 4-fold rate gain to out-of-phase acceptor vibrations amplified by low temperature.
Relativistic CCSD needs only 3% of its doubles amplitudes
SVD-based compression with a 1e-4 cutoff keeps heavy-element correlation energies within 1 kJ/mol.
Imaging electron and hydrogen motion in ammonia in real time
A charge-pair analysis of ultrafast electron diffraction separates valence-electron motion from N-H bond breaking.
Nanodroplets measure magnetic moments of cold salt molecules
FeCl2 and CoCl2 match bulk values; dimers are antiferromagnetic, opening a route to cluster magnetometry.
· “Stern-Gerlach deflection of cryogenically cold polyatomic molecules in superfluid nanodroplets”
Multipole coupling dominates OLED triplet quenching
Counting dipole-quadrupole transfer raises the predicted quenching radius from ~3 to ~3.6 nm, matching device data.
One argon ion line measures the condensate fraction of a gas jet
Absolute line intensities plus emission cross sections yield monomer density, condensate fraction, and cluster density.
· “Diagnostics of the condensate fraction in a clustered supersonic argon jet”
Active learning cuts neutron-structure training data by 75%
Uncertainty sampling needs a quarter of the simulated data, and streaming trims training time by ~20%.
Excited-state coupling closes ultracold K+KRb gap
Adding the first excited electronic state lifts the zero-temperature rate to 1.32e-10 cm3/s, inside the experimental error bar.
Spin-locked current from isotropic light in chiral molecules
Isotropic light, spin-resolved detection: the current follows the spin axis and flips with the enantiomer.
· “Spin-current correlations in photoionization of chiral molecules”
Photocurrent maps expose a molecule's dual excited-state character
Zero-bias light-STM images on a single PTCDA anion reveal both configurations of its excited doublet state.
· “Disentangling the components of a multiconfigurational excited state in isolated chromophore”
Vibrating molecular cage squeezes hydrogen past 400 GPa
Simulations show six trapped hydrogen atoms passing through metallic-liquid and solid phases inside a molecular cage.
Sodium dimer state lives 43.5 nanoseconds
Temperature-extrapolated measurement agrees with theoretical 43.334 ns, validating bound-free decay calculations.
Cluster size flips xenon bremsstrahlung to polarization mode
Absolute cross sections show clusters of 3000+ atoms emit mostly polarization bremsstrahlung, not ordinary bremsstrahlung.
· “Size effect on polarization bremsstrahlung emission from xenon clusters”
Trapped molecules stay nearly free yet strongly align inside C60
DFT plus rigid-rotor analysis predicts N2 and AlF lock to the cage axis while keeping gas-phase constants.
First X-ray peaks predicted for CN+
Calculations place the 0-0 absorptions at 280.7, 279.6, and 285.8 eV and assign CN- to a degenerate π* transition.
A neutral metal hemisphere makes a 10^8 V/m field
Quantum shell effects survive the flat cut, giving an uncharged cluster a built-in field for nanoscale tweezers.
Exact formula converts any spherical harmonic to Cartesian monomials
Closed coefficients for all angular momenta, tested in a multipole Hartree potential that converges at ℓ=14 for La2.
· “Spherical to Cartesian Coordinates Transformation for Solid Harmonics Revisited”
Skyrmion lattice held up by quadrupole entropy at 5 K
Magnetic quadrupole moments on spin trimers explain coexisting anisotropies and stabilize the skyrmion phase
Compact X-ray laser scheme could seed free-electron lasers
Crystal Bragg mirrors plus an ion-source gain medium aim to deliver stable coherent X-rays from a lab-scale device.
· “A Compact X-Ray Laser with Ion Source and Crystal Cavity”
Vortex lattice raises critical temperature at fixed volume
Simulations show the vortex array shields the condensate from thermal fluctuations, not just marks it.
· “Vortex lattice melting and critical temperature shift in rotating Bose-Einstein condensates”
Scattered photoelectrons drive lithium ionization in helium droplets
In large helium droplets, scattered electrons beat direct photons at ionizing lithium dopants.
Antenna atom flips the sign of photoelectron circular dichroism
A helium atom can transfer circular polarization to camphor and reverse the electron asymmetry.
Femtosecond clock captures Mg cluster formation at 450 fs
Delayed photoelectron band reveals collapse of a metastable Mg foam and energy pooling in helium nanodroplets.
Coulomb explosion tracks vibrating dimers for 300 ps
A 50-fs laser pulse maps bond length in K2 and Rb2 on helium droplets through 180 vibrations
Minmax-FEM solves two-center Dirac equation to 1e-23
Finite-element minmax method pins H2+ and heavy Th2^179+ energies with fractional uncertainties down to 1e-23.
· “High-precision minmax solution of the two-center Dirac equation”
A thousandfold quantum-battery storage boost from dark triplets
By charging through bright states and storing in dark ones, excitonic quantum batteries can beat the superradiance leak.
· “Molecular triplets and other metastable states for excitonic quantum batteries”
Universal s-wave resonance reached in shielded dipolar fermion mixtures
Microwave parameters tune the interaction without breaking the protection that keeps losses low, opening a path to stable degenerate samples
· “Tunable Field-Linked s-wave Interactions in Dipolar Fermi Mixtures”
Coarse-grained water matches all-atom thermodynamics within 1 k_B
Block-diagonal Hessian cuts coarse-graining cost to all-atom levels while keeping heat capacity and structure nearly exact.
Compact ECR source hits H- density of 5.5e10 cm-3 at 500 W
Mass spectrometry plus collisional-loss corrections suggest this low-power source rivals kilowatt-class negative-ion sources.
No 2D fingerprints needed: 3D descriptor matches drug baselines
Repurposed simulation features match 2D fingerprint baselines and distinguish mirror-image molecules.
· “Rem3Di: Learning smooth, chiral 3D molecular descriptors from atomistic foundation models”
Gamma-distributed temperatures yield a q-exponential law
A Laplace average over local inverse temperatures converts the Boltzmann factor into a two-parameter decay law for complex systems.
Model adds four-phonon scattering to predict solid infrared optics
The simplified approach matches experiments on MgO and TiO2 at low computational cost.
· “A first-principles approach for predicting infrared optical properties of solids”
DFT choice shifts NO electron scattering resonances near 1 eV
Target properties from different functionals move resonance positions and alter cross sections in R-matrix models of nitric oxide.
· “Influence of DFT Functionals on Low-Energy Electron Scattering Cross Sections of Nitric Oxide”
Multiple-zone surface ion trap maps magnetic gradients at sub-mm scale
Trapped ions in a scalable chip design enable pT-sensitive detection and precise field gradient measurements across separate zones.
· “Scalable surface ion trap design for magnetic quantum sensing and gradiometry”
Beta exceeds 1 in OCS electron-impact ion-pair breakup
Angular distributions show partial-wave shifts that invalidate the dipole-Born model and point to quasi-resonant superexcited states.
Buckling lifts spin degeneracy in molecular rings
On Au(111), planar six-membered spin rings stay symmetric, while buckled five-membered rings localize spins.
· “Quantum Spin-1/2 Rings Built from [2]Triangulene Molecular Units”
Logarithmic coupling breaks scale invariance in 2D Bose gases
Density-dependent interaction strength lets researchers compute quantum-droplet states and breathing modes without extra parameters.
· “Generalized Gross-Pitaevskii Equation for 2D Bosons with Attractive Interactions”
Ozone double ionization yields excited oxygen ions
First valence double-ionization spectrum and calculations show both ground and excited O+ fragments, revealing more breakup pathways than此前已
Rotation probe finds Hagena law undercounts large clusters
Ionization-free rotation probe sizes argon and neon clusters; finds Hagena scaling law undercounts large ones.
Ultrastrong coupling shifts bistability but keeps its switching rule
Counter-rotating light–matter terms shift the effective detuning and nonlinearity, moving the S-curve and hysteresis loop.
· “Bistability of Exciton-Photon Microcavities in the Ultrastrong-Coupling Regime”
One equation governs all seven four-level superradiant bursts
SU(4) tetrahedral lattice unifies tripod, diamond, and five other topologies under a single rate equation, with peak intensity scaling as N^
· “Multi-channel collective dissipation via the symmetric irreducible representation of SU(4)”
Analytical electron-impact cross sections from ab initio data
MC-BE/TMMM matches benzene and naphthalene experiments near threshold using only TDDFT amplitudes
Atoms tunnel a lossy molecular barrier by interference
A dark collisional state opens a narrow transparency window inside a Feshbach resonance
Slater tails correct PADs for O2- and NO-
Augmenting Gaussian bases with exponential tails aligns theory with measured angular distributions except in the weakest-binding cases.
Larger water clusters eject more protons in lasers without extra ionization
Simulations show proton transfer and dissociation rise sharply from dimer to tetramer while net charge per molecule stays nearly constant.
· “Size Effects in the Strong-Field Ionization and Dissociation Dynamics of (H₂O)_n (n=1-4)”
SEM diffraction sets 60% lower limit on beam coherence
Interference between electrons 0.031 per angstrom apart in gold and graphene patterns yields the value at 30 keV.
Bosonic cluster energies converge independent of cutoff
Leading-order theory uses only dimer and trimer energies to predict results up to 15 particles that match realistic potentials.
Dual-beam trap switches aerosol to orbital motion
Axial separation starts circulation and lateral offset tunes frequency for dynamical sensing
Stochastic Schrödinger matches Lindblad for Na2-cavity loss
It remains accurate yet cheaper, while rotation adds nonadiabatic effects through light-induced conical intersections
· “Light-induced nonadiabatic dissipative quantum dynamics of the Na2 molecule”
Tensor networks split entangled dynamics into independent tasks on separate quantum comput
The decomposition enables asynchronous execution across heterogeneous hardware and produces vibrational spectra of a protonated water cluste
· “Tensor-Network-Based Distributed Quantum Dynamics on Independent Quantum Computers”
23 coupled states raise HeH+ recombination cross section
Wave-packet results on a large manifold show rotational couplings boost the rate well above previous models
Rainbow RABBITT tracks Rabi wave-packet phase via sideband dispersion
Intra-sideband phase varies by nearly pi across its width and flattens at exact resonance, showing the method reads accumulated dynamical ph
Chirality labels each topological edge with opposite handedness
Left edge state localizes on left-handed molecules and right edge on right-handed ones in dimerized dipolar arrays.
· “Topological Edge States from Molecular Chirality: A General Framework for Dimerized Dipolar Arrays”
Emerging amines overtake DMA in urban particle formation
Beijing measurements show DEA and PZ drive more nucleation than dimethylamine, requiring updates to standard urban aerosol models
· “Emerging Amines reshape the paradigm of urban atmospheric particle formation”
Mobile agent converts catalyst requests into experiment-matching simulations
ChatMOSP retrieves parameters from literature to reproduce Pd nanoparticle shape changes and Pt activity oscillations under CO oxidation con
· “ChatMOSP: A Chemistry-Grounded Mobile Agent for Working-State Catalyst Simulations”
MACE tops benchmarks for accurate ML infrared spectra
Tests on five neural potentials show equivariant models like MACE and PaiNN generalize better to new molecules than SchNet.
· “Benchmarking machine-learned interatomic potentials for molecular infrared spectroscopy”
Quantum nuclei cut proton bias in asymmetric H-bond from 82% to 61%
Accelerated simulations treating both electron correlation and nuclear quantum effects shift the shared proton closer to the bond center.
Two trapping sites shape Cs fluorescence in argon
Spectroscopy and simulations link distinct doublet and singlet behaviors to different lattice environments and reorganization.
Asteroid black holes split 9.9 GHz line into 2 GHz radio forest
Tidal splitting of bound hydrogen atoms creates an enhanced absorption signature that radio surveys could use to constrain PBH dark matter.
· “The Gravitational Spectral Radio Forest: A Signature of Primordial Black Holes”
Natural orbitals outperform Dyson ones for helium drop density
In clusters of 5-20 atoms both sets reconstruct the density, but natural orbitals from the density matrix do so more accurately, with thegap
Analytical model gives effusive source intensity for any molecular flow
Covers transparent to opaque regimes in long tubes and recovers standard axial flux for source design.
· “Analytical emission model for the design of primary effusive sources”
Global fit improves OH+ spectroscopic constants
New IR and THz measurements of hyperfine-resolved transitions in a cold ion trap tighten the ground-state parameters of the molecular ion.
· “Hyperfine-Resolved Rovibrational and Rotational Spectroscopy of OH^+ (X ³Sigma^-)”
Nanocavity fields shift excitonic modes proportionally in radical aggregates
Dark states sharpen while bright states diverge at asymmetric positions, showing direct electric control over long-lived collective modes.
· “Locally-Induced Stark Shifts of Collective Excitonic Modes in Polyradical Aggregates”
2025 workshop reflections map open problems in cluster science
Contributors share perspectives on unresolved questions in nanocluster electron dynamics and behavior
Individual nonlinearities appear in linear spectra of emitter arrays
Emitter interactions cause Raman-type anharmonicities to show as sidebands on collective resonances, allowing control of spectral features.
· “Hidden optical nonlinearities in linear spectra of quantum emitter arrays”
