Search results for "interaction [electron p]"

2021

The reaction of :AlAriPr8 (AriPr8 = C6H-2,6-(C6H2-2,4,6-iPr3)2-3,5-iPr2) with ArMe6N3 (ArMe6 = C6H3-2,6-(C6H2-2,4,6-Me3)2) in hexanes at ambient temperature gave the aluminum imide AriPr8AlNArMe6 (1). Its crystal structure displayed short Al-N distances of 1.625(4) and 1.628(3) A with linear (C-Al-N-C = 180°) or almost linear (C-Al-N = 172.4(2)°; Al-N-C = 172.5(3)°) geometries. DFT calculations confirm linear geometry with an Al-N distance of 1.635 A. According to energy decomposition analysis, the Al-N bond has three orbital components totaling -1350 kJ mol-1 and instantaneous interaction energy of -551 kJ mol-1 with respect to :AlAriPr8 and ArMe6N:. Dispersion accounts for -89 kJ mol-1, w…

Weak interactions between trivalent pnictogen centers: computational analysis of bonding in dimers X3E...EX3 (E = pnictogen, X = halogen).

2009

The nature of weak interactions in dimers X(3)E...EX(3) (E = N-Bi, X = F-I) was investigated by wave function and density functional theory (DFT)-based methods. Out of the 20 systems studied, 10 are found to be bound at the CP-MP2 and LMP2 levels of theory. Detailed partition of the interaction energy into different components revealed that dispersion is the primary force holding the dimers together but there also exists an important ionic component whose contribution increases with increasing halogen size. As expected, standard density functionals fail to describe bonding in the studied systems. However, the performance of DFT methods can be easily improved via empirical dispersion correct…

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 …

Precision luminosity measurements at LHCb

2014

Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy $\sqrt{s}$. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for $\sqrt{s}$ = 2.76, 7 and 8 TeV (proton-proton collisions) and for $\sqrt{s_{NN}}$ = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves sig…

Defining Interaction Design Patterns to Extract Knowledge from Big Data

2018

[EN] The Big Data domain offers valuable opportunities to gain valuable knowledge. The User Interface (UI), the place where the user interacts to extract knowledge from data, must be adapted to address the domain complexities. Designing UIs for Big Data becomes a challenge that involves identifying and designing the user-data interaction implicated in the knowledge extraction. To design such an interaction, one widely used approach is design patterns. Design Patterns describe solutions to common interaction design problems. This paper proposes a set of patterns to design UIs aimed at extracting knowledge from the Big Data systems data conceptual schemas. As a practical example, we apply the…

Interaction Theory and the Social Network

1967

Interaction theorists have delineated the close association in friendship relations between value consensus, affectional closeness, and interaction. Categorical investigations of the social network have focused upon frequency of interaction with friends and kin. In the present paper a componential theory of attraction in the social network is developed in order to link previous theoretical discussions with the empirical social network categories. Two attractional variables, one based upon consensus and the other upon positive concern, are perceived as interpreting friendship and kinship involvements. Consensus tends to be modal in friendship and positive concern in kinship, though there are…

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…

Modeling of Retention in Reversed Phase Liquid Chromatography

2015

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…

N-Heterocyclic Carbenes with Inorganic Backbones:  Electronic Structures and Ligand Properties

2008

The electronic structures of known N-heterocyclic carbenes (NHCs) with boron, nitrogen, and phosphorus backbones are examined using quantum chemical methods and compared to the experimental results and to the computational data obtained for a classical carbon analogue, imidazol-2-ylidene. The sigma-donor and pi-acceptor abilities of the studied NHCs in selected transition-metal complexes are evaluated using a variety of approaches such as energy and charge decomposition analysis, as well as calculated acidity constants and carbonyl stretching frequencies. The study shows that the introduction of selected heteroatoms into the NHC backbone generally leads to stronger metal-carbene bonds and t…