A5049593171- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Synthesis and Properties of Aromatic Compounds
- Spectroscopy and Quantum Chemical Studies
- Molecular spectroscopy and chirality
- Photochemistry and Electron Transfer Studies
- Molecular Spectroscopy and Structure
- Analytical Chemistry and Chromatography
- Advanced Physical and Chemical Molecular Interactions
- Protein Structure and Dynamics
- DNA and Biological Computing
- Chemical Synthesis and Analysis
- Molecular Junctions and Nanostructures
- Innovations in Educational Methods
- Fullerene Chemistry and Applications
- Origins and Evolution of Life
- Educational Games and Gamification
- Mechanical and Optical Resonators
- Inorganic and Organometallic Chemistry
- Various Chemistry Research Topics
- Carbohydrate Chemistry and Synthesis
- Atmospheric Ozone and Climate
- Astrophysics and Star Formation Studies
- Nonlinear Optical Materials Research
- Nuclear Physics and Applications
University of Modena and Reggio Emilia
1999-2023
University of Buenos Aires
2005
University of Salerno
1999-2005
Dalton is a powerful general-purpose program system for the study of molecular electronic structure at Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, Møller-Plesset, configuration-interaction, and coupled-cluster levels theory. Apart from total energy, wide variety properties may be calculated using these electronic-structure models. Molecular gradients Hessians are available geometry optimizations, dynamics, vibrational studies, whereas magnetic resonance optical...
Traces of magnetizability, traces magnetic shielding at the hydrogen nuclei, and nucleus-independent chemical shift are not reliable aromaticity quantifiers for planar conjugated hydrocarbons. A measure is provided by out-of-plane tensor components, whose magnitude influenced pi-ring currents. The failure in this regard was proved molecule shown abstract graphic, sustaining a diatropic pi-current. validity ring-current model reaffirmed. [structure: see text]
Ab initio magnetically induced π-electron (first-order) current density maps and second-order magnetic properties, i.e., magnetizabilies, proton, 13 C shielding tensors, calculated at coupled Hartree−Fock level of theory by means the continuous transformation origin method (CTOCD), are presented for a series polycyclic aromatic hydrocarbons. The reliability is documented nice agreement between theoretical values principal magnetizabilities proton shieldings corresponding experimental data...
The differential Biot-Savart law provides simple models for the π ring currents induced in diatropic and paratropic planar conjugated molecules by a perpendicular magnetic field. model predictions are confirmed ab initio maps of nuclear shielding density. effects on protons carbon atoms from closest furthest segments current loop easily interpreted.
We report for the first time an extended series of correlated origin independent calculations nuclear magnetic shielding tensors using approach continuous transformation current density to annihilate its diamagnetic contribution. A systematic study was undertaken develop optimal basis sets H, C, N, O, F shieldings, looking best compromise between accuracy and size. Beyond Hartree–Fock were carried out at two levels accuracy, multiconfigurational self-consistent field based on complete active...
The quantum mechanical current density induced in a molecule by an external magnetic field is invariant to translations of the coordinate system. This fundamental symmetry exploited formally annihilate diamagnetic contribution via approach "continuous transformation origin density-diamagnetic zero" (CTOCD-DZ). relationships obtained this method for shielding at nuclei are intrinsically independent system any approximate computational scheme relying on algebraic approximation. authors report...
It is shown via a large series of numerical tests on two fundamental organic molecules, the $L\ensuremath{-}\ensuremath{\alpha}$-amino acid L-valine and sugar precursor hydrated D-glyceraldheyde, that ab initio calculation parity-violating energy shift, at random-phase approximation level accuracy, provides results are about one order magnitude larger than those obtained by means less accurate methods employed previously. These findings would make more plausible hypothesis electroweak...
Magnetic susceptibility and nuclear magnetic shielding at the nuclei of s-indacene have been evaluated by a series different approximations large Gaussian basis set. An ab initio model field induced current density was developed, showing that intense paramagnetic flow takes place within π electrons. It causes strong upfield chemical shift protons attached to hexagonal pentagonal rings. The tensor is typical diamagnetic molecule but characterized small anisotropy. Group-theoretical methods...
Symmetry arguments show that the ring-current model proposed by Pauling, Lonsdale, and London to explain enhanced diamagnetism of benzene is flawed an intrinsic drawback. The minimal basis set six atomic 2p orbitals taken into account develop such a inherently insufficient predict paramagnetic contribution perpendicular component magnetic susceptibility in planar ring systems as benzene. Analogous considerations can be made for hypothetical H(6) cyclic molecule. A allowing extended sets...
A coupled Hartree-Fock procedure has been employed to estimate the frequency shift in infrared spectra of S and R enantiomers CHFClBr molecule due parity-violating electroweak interaction. The calculations indicate that a resolving power $\ensuremath{\nu}/\ensuremath{\Delta}\ensuremath{\nu}\ensuremath{\approx}1\ifmmode\times\else\texttimes\fi{}{10}^{16},$ i.e., three orders magnitude larger than obtained recent experiments, would be necessary detect effects. largest was found for C-Cl stretching.
Abstract The differential Biot–Savart law of classical electrodynamics was applied to develop a ring current model for the magnetic shielding carbon nucleus in benzene. It is shown that local effect π currents, induced by field normal molecular plane, on $\sigma_{\|}^{\rm C}$ out‐of‐plane tensor component vanishes. However, approximately 10% due contributions from density region other atoms. Magnetic maps obtained via quantum mechanical procedures confirm predictions model. Copyright © 2004...
A benchmark study of several correlated second-order methods for frequency-dependent polarizabilities has been carried out. For the benchmark, a set 14 (hetero)aromatic medium-sized molecules chosen. first time, CC3 are reported these using Sadlej's polarized triple-ζ basis set, and subset were obtained at level also with larger aug-cc-pVTZ set. These values used as reference benchmarking methods: SOPPA, SOPPA(CC2), SOPPA(CCSD), CC2, well CCSD. The influence different sets, aug-cc-pVDZ,...
An additive scheme for resolving average optical rotatory power of a molecule into atomic contributions, based on the acceleration gauge electric dipole, and/or torque formalism, has been applied to hydrogen peroxide. Extended calculations have carried out test reliability partition method. Gross isotropic contributions molecular property from oxygen and atoms evaluated. The force gauges provide different numerical values contributions.
A coupled Hartree-Fock procedure has been employed to estimate the parity-violating energy contribution due electroweak interaction in vicinity of transition point a chemical reaction path starting from achiral reagents and producing chiral CHFClBr molecule. The calculations demonstrate that (i) S enantiomer is product more stable than its mirror image by approximately 1x10(-17) hartree; (ii) state reaction, activated complex evolving toward S-CHFClBr species stable, 2.3x10(-17) hartree,...
Four theoretical methods, using continuous transformation of the origin current density (CTOCD) to annihilate either diamagnetic or paramagnetic contribution, have been employed at coupled Hartree–Fock level accuracy evaluate magnetic susceptibility and nuclear shielding five planar molecules with chemical formula C6H6. The results compared corresponding estimates from basis sets London orbitals, showing near quality calculated values practicality CTOCD approaches. Maps streamlines intensity...
Space exploration and astronomical objects are extensively used in modern board games. These games can be an entertaining way to present educational contents on Astrophysics-related topics, by acknowledging the importance beauty of Space. However, careful consideration mechanics, messages, themes is required achieve this goal. We a classification system for presence Astronomy, Astrophysics, Science 2000 most popular games, where categorised according their complexity actual scientific...
Abstract A series of theoretical procedures, relying on the conventional common-origin and distributed-origin approaches, adopting extended gaugeless as well London basis sets, have been applied at Hartree-Fock level accuracy to predict magnetic susceptibilities nuclear shieldings four molecular systems that aroused particular interest discussion concerning their aromatic character. The results are near quality. Comparison with experimental values for seems indicate latter need be revised....
R. Toniolo 1G. Inchingolo2S. Casu3G. Contino4V. La Parola4R. Leoni5S. Varano6A. Zanazzi2A. Ligabue7S. Ricciardi8
PIXEL - Picture (of) the Universe is a board game developed by INAF Italian National Institute for Astrophysics in collaboration with GAME Science Research Center. The simulates astrophysics research environment, particularly emphasising observation and study of cosmic bodies at different resolutions. Image resolution crucial element astrophysics, but intrinsic complexity challenges making high-resolution images distant are not easily generally perceivable. We envisioned driven this...