A5036378256- Surface Chemistry and Catalysis
- Advanced Chemical Physics Studies
- Molecular Junctions and Nanostructures
- Machine Learning in Materials Science
- High-pressure geophysics and materials
- Surface and Thin Film Phenomena
- Semiconductor materials and devices
- Graphene research and applications
- Force Microscopy Techniques and Applications
- Diamond and Carbon-based Materials Research
- Boron and Carbon Nanomaterials Research
- Electronic and Structural Properties of Oxides
- Semiconductor materials and interfaces
- nanoparticles nucleation surface interactions
- Crystallization and Solubility Studies
- Catalytic Processes in Materials Science
- Advanced Materials Characterization Techniques
- Advanced biosensing and bioanalysis techniques
- Advanced ceramic materials synthesis
- X-ray Diffraction in Crystallography
- 2D Materials and Applications
- Silicon and Solar Cell Technologies
- Advanced Condensed Matter Physics
- Electron and X-Ray Spectroscopy Techniques
- Microstructure and mechanical properties
Fritz Haber Institute of the Max Planck Society
2024-2025
Technische Universität Berlin
2025
Istituto Officina dei Materiali
2022-2024
University of Reggio Calabria
2024
University of Milan
2019-2024
University of Trieste
2008-2020
King's College London
2011-2020
Elettra-Sincrotrone Trieste S.C.p.A.
2020
University of Cologne
2020
University of Auckland
2018
Al(110) has been studied for temperatures up to 900 K via ensemble density-functional molecular dynamics. The strong anharmonicity displayed by this surface results in a negative coefficient of thermal expansion, where the first interlayer distance decreases with increasing temperature. Very shallow channels oscillation second-layer atoms direction perpendicular support anomalous contraction, and provide novel mechanism formation adatom-vacancy pairs, preliminary disordering premelting...
We present a molecular dynamics scheme which combines first-principles and machine-learning (ML) techniques in single information-efficient approach. Forces on atoms are either predicted by Bayesian inference or, if necessary, computed on-the-fly quantum-mechanical (QM) calculations added to growing ML database, whose completeness is, thus, never required. As result, the is accurate general, while progressively fewer QM calls needed when new chemical process encountered for second subsequent...
Two-dimensional supramolecular clusters and chains are observed upon submonolayer deposition of 1-nitronaphthalene (NN) onto reconstructed Au(111). The molecules become pseudochiral adsorption. Their handedness is determined from high-resolution scanning tunneling microscope images local-density calculations. Modeling shows that hydrogen bonds cause the self-assembly. Clusters mutually interact via electrostatic repulsion.
We present a novel scheme to accurately predict atomic forces as vector quantities, rather than sets of scalar components, by Gaussian process (GP) regression. This is based on matrix-valued kernel functions, which we impose the requirements that predicted force rotates with target configuration and independent any rotations applied database entries. show such covariant GP kernels can be obtained integration over elements rotation group $\mathit{SO}(d)$ for relevant dimensionality $d$....
The electronic structure and morphology of ultrathin MgO films epitaxially grown on Ag(001) were investigated using low-temperature scanning tunneling spectroscopy microscopy. Layer-resolved differential conductance (dI/dU) measurements reveal that, even at a film thickness three monolayers, band gap about 6 eV is formed corresponding to that the MgO(001) single-crystal surface. This finding confirmed by layer-resolved calculations local density states based functional theory.
The microscopic mechanism of platinum cluster nucleation on DNA templates is studied by first-principle molecular dynamics simulations. We find that Pt(II) complexes bound to can form strong Pt−Pt bonds with free Pt after a single reduction step, and may thus act as preferential sites. This confirmed series experiments, in which we achieve purely heterogeneous growth DNA, use it fabricate metal necklaces unprecedented thinness regularity.
We describe and test a novel molecular dynamics method which combines quantum-mechanical embedding classical force model optimization into unified scheme free of the boundary region, transferability problems these techniques, taken separately, involve. The is based on idea augmenting unique, simple parametrized by incorporating in it, at run time, information necessary to ensure accurate trajectories. tested number silicon systems composed up approximately 200 000 atoms.
Two-dimensional supramolecular honeycomb networks with cavities of an internal diameter 2.95 nm were formed by the self-assembly 4,4',4' '-benzene-1,3,5-triyl-tribenzoic acid (BTA) on a Ag(111) surface at room temperature. Annealing to higher temperatures resulted in two sequential phase transformations into closer-packed arrangements. The are associated stepwise deprotonation carboxylic groups. voids network BTA have suitable size for construction hierarchical structures guest molecules....
The uncatalyzed edge growth of carbon nanotubes was investigated by first-principles molecular dynamics simulations. At experimental temperatures the open end single-walled closed spontaneously into a graphitic dome, which may explain why these do not grow in absence transition metal catalysts. On other hand, chemical bonding between edges adjacent coaxial tubes (“lip-lip” interactions) trapped double-walled nanotube metastable energy minimum, thus preventing dome closure. These calculations...
We present investigations on noncovalent bonding and supramolecular self-assembly of two related molecular building blocks at a noble metal surface: 4-[trans-2-(pyrid-4-yl-vinyl)]benzoic acid (PVBA) 4-[(pyrid-4-yl-ethynyl)]benzoic (PEBA). These rigid, rodlike molecules comprising the same complementary moieties for hydrogen bond formation are comparable in shape size. For PVBA, ethenylene moiety accounts two-dimensional (2-D) chirality upon confinement to surface; PEBA is linear thus 2-D...
The ordering of 4-[trans-2-(pyrid-4-yl-vinyl)] benzoic acid, a two-dimensional chiral species, was studied by scanning tunneling microscopy at noble metal surfaces. Homochiral molecules self-assemble in supramolecular hydrogen-bonded twin chains, which order nanogratings where the chirality is strictly correlated over entire $\ensuremath{\mu}\mathrm{m}$ domains without intimate molecular contact. Model simulations indicate that underlying mesoscopic resolution associated with chains acting...
Medium size HPC clusters play an important role in the landscape that they provide both training environment for system scalability and a flexible production field large class of numerical problems. In this poster we present CRESCO4, latest medium cluster purchased by ENEA, operation since few months. CRESCO4 is part family systems, all integrated within ENEAGRID, infrastructure cloud computing, which includes computational facilities installed at several ENEA sites Italy.
Lights, camera, action! The general mechanism of biomolecular recognition introduced by Pauling more than 50 years ago has now been brought to the movie screen (see still frame; D: D-Phe-D-Phe, L: L-Phe-L-Phe). With STM movies, chiral-recognition process individual adsorbed di-phenylalanine molecules is followed illustrate dynamic induced-fit at single-molecule level. Supporting information for this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z700194_s.html...
We provide a definition and explicit expressions for $n$-body Gaussian Process (GP) kernels which can learn any interatomic interaction occurring in physical system, up to contributions, value of $n$. The series is complete, as it be shown that the "universal approximator" squared exponential kernel written sum kernels. These recipes enable choice optimally efficient force models each target confirmed by extensive testing on various materials. furthermore describe how "mapped" equivalent...
We present an ab initio investigation of the structural and electronic properties (0001) $\ensuremath{\alpha}\ensuremath{-}\mathrm{q}\mathrm{u}\mathrm{a}\mathrm{r}\mathrm{t}\mathrm{z}$ surface. Five different models this surface are generated by cleavage bulk followed atomic relaxation constant-temperature molecular dynamics. The most favorable reconstruction presents unexpected densification two uppermost layers ${\mathrm{SiO}}_{2}$ tetrahedral units, with three-membered six-membered rings...
Ab initio total-energy calculations have been performed on a parallel computer to study the formation and migration energies of cation anion vacancies in MgO. The are made framework density functional pseudopotential theory, using supercell method, with valence orbitals expanded plane waves. relaxed ground state is determined by conjugate-gradients minimization respect plane-wave coefficients occupied orbitals. calculated defect shown be remarkably close agreement experiment values obtained...
The initial nucleation of platinum clusters after the reduction K(2)PtCl(4) in aqueous solution is studied by means first principles molecular dynamics simulations. A reaction mechanism leading to a Pt dimer revealed both gas-phase simulations and which model environment. key step observed process formation Pt-Pt bond between Pt(I) complex an unreduced Pt(II) complex. In light this result, we discuss nanoparticles. generally accepted model, particles starts only when critical concentration...