Search results for "interaction potential"
showing 10 items of 11 documents
Monte Carlo Simulations of Au38(SCH3)24 Nanocluster Using Distance-Based Machine Learning Methods
2020
We present an implementation of distance-based machine learning (ML) methods to create a realistic atomistic interaction potential to be used in Monte Carlo simulations of thermal dynamics of thiol...
Clusterization and strong coupled-channels effects in deuteron interaction with $^9$Be nuclei
2019
Angular distributions of protons, deuterons, tritons and alpha particles emitted in the d + alt;supagt;9alt;/supagt;Be reaction at Ealt;subagt;labalt;/subagt;=19.5 and 35.0 MeV have been measured.a#13; The elastic scattering channel is analysed in the framework of both the Optical Model and the Coupled-Channel approach. a#13; The interaction potential of the alt;iagt;dalt;/iagt; + alt;supagt;9alt;/supagt;Be system is calculated in the framework of the Double-Folding model using the α+α+alt;iagt;nalt;/iagt; three-body wave function of the alt;supagt;9alt;/supagt;Be nucleus.a#13; The (alt;iagt;dalt;/iagt;,alt;iagt;palt;/iagt;) and (alt;iagt;dalt;/iagt;,alt;iagt;talt;/iagt;) one-nucleon-transf…
On the electronic coupling of the C=O stretching vibrations in Cl(2)Pt(malonate)(-).
2001
Ab initio calculations on the complex Cl(2)Pt(malonate)(-) have been performed to estimate the magnitude and the source of the splitting between the symmetric and antisymmetric C=O stretches. It is shown that a large part of the splitting can result from pure electronic coupling mediated via the pi-structure of the ligand. Calculations have also been performed on the free ligand malonate(-) and the neutral malonaldehyde that show decreasing electronic coupling, which is consistent with the decreasing resonance stabilization. A simple effective C=O interaction potential has been produced for Cl(2)Pt(malonate)(-) that is used to estimate the electronic splitting of the 1600 cm(-1) IR band to …
The Role Of Complex Leadership In Interfirm Strategic Networks: Enabling Effect Versus Emergence
2014
In today's knowledge-based economy, the sources of competitive advantage lie more and more in webs of relationships among a variety of firms that over time originate the emergence of interfirm strategic networks. The paper aims to shed light on the role of complex leadership exerted by network central firms in promoting and supporting network interactions and the ensuing processes of knowledge and resource transfer and diffusion. Processes on which the network-based sources of competitive advantage are rooted. In the attempt to make the proposed contribution, on the one hand, we underscore the emergent nature of network interactions stemming from the self-organizing behaviors that spontaneo…
Mobility of the Singly-Charged Lanthanide and Actinide Cations: Trends and Perspectives
2020
The current status of gaseous transport studies of the singly-charged lanthanide and actinide ions is reviewed in light of potential applications to superheavy ions. The measurements and calculations for the mobility of lanthanide ions in He and Ar agree well, and they are remarkably sensitive to the electronic configuration of the ion, namely, whether the outer electronic shells are 6s, 5d6s or 6s$^2$. The previous theoretical work is extended here to ions of the actinide family with zero electron orbital momentum: Ac$^+$ (7s$^2$, $^1$S), Am$^+$ (5f$^7$7s $^9$S$^\circ$), Cm$^+$ (5f$^7$7s$^2$ $^8$S$^\circ$), No$^+$ (5f$^{14}$7s $^2$S) and Lr$^+$ (5f$^{14}$7s$^2$ $^1$S). The calculations rev…
Structure and dynamics of B2O3 melts and glasses: From ab initio to classical molecular dynamics simulations
2019
Abstract Boron oxide (B2O3) is investigated by a combination of ab initio (DFT-based) molecular dynamics (MD) simulations and classical MD simulations. From the trajectories of the ab initio MD simulation, we derive a three-body interaction potential which is used in classical MD simulations to study various structural and dynamic properties on larger time and length scales than possible in the ab initio simulations. Differences and similarities to the structure and dynamics of other network glass formers such as SiO2 and GeO2 are discussed. Moreover, various properties as obtained from the simulations are compared to those from experiments of B2O3.
The spiked harmonic oscillatorV(r)=r 2+λr −4 as a challenge to perturbation theory
1991
The standard weak- and strong-coupling perturbation series are interpreted as extreme special cases of expansions obtainable within the framework of Rayleigh-Schroedinger perturbation theory with non-diagonal propagators and unspecified zero-order energies. The formalism of the latter type is then tested by our strongly singular example. It proves suitable for applications in the domain of virtually arbitrary couplings. A few related technicalities and especially the quadruple problem of convergence are also discussed.
Rotational excitation of mono- and doubly-deuterated water by hydrogen molecules
2011
Rate coefficients for rotational transitions in HDO and D2O induced by H2 collisions below 300 K are presented. Calculations have been performed at the close-coupling and coupledstates levels with the deuterated variants of the H2O–H2 interaction potential of Valiron et al. The HDO–H2 and D2O–H2 rate coefficients are compared to the corresponding rate coefficients for HDO–He and H2O–H2, respectively. Significant differences are observed. In particular the new HDO rate coefficients are found to be significantly larger (by up to three orders of magnitude) than the corresponding HDO–He rate coefficients. The impact of the new HDO rate coefficients is examined with the help of non-LTE radiative…
Calculated Line Broadening Coefficients in the nu2 Band of CH3D Perturbed by Helium
2003
International audience; Line broadening coefficients have been calculated, at room temperature, for lines in the P and R branches of the nu2 band of monodeuterated methane. A properly symmetrized semiclassical model with parabolic relative trajectories has been used. Two interaction potential models have been considered. The first is a Lennard-Jones type atom-atom potential, while the second one was derived from ab initio calculations. The calculated line widths were compared to the available experimental data and a satisfactory agreement was found, although the model contains no other adjustable parameters than the four atomic Lennard-Jones ones. Nonetheless, failures of calculations have …
Rotational quenching of monodeuterated water by hydrogen molecules
2011
Cross sections and rate coefficients for low lying rotational transitions in HDO induced by para and ortho-H(2) collisions are presented for the first time. Calculations have been performed at the close-coupling and coupled-states levels with the deuterated variant of the H(2)O-H(2) interaction potential of Valiron et al. [J. Chem. Phys., 2008, 129, 134306]. Rate coefficients are presented for temperatures between 5 and 100 K and are compared to the corresponding rates for H(2)O and D(2)O. Significant differences caused by the isotopic substitution, in particular the C(2v) symmetry breaking, are observed. Finally, our rates are found to be significantly larger (by up to three orders of magn…