Quantum mechanical and quasiclassical investigation of the time domain nonadiabatic dynamics of NO2 close to the bottom of the X2A1-A2B2 conical intersection

We use the effective Hamiltonian that we recently fitted against the first 306 experimentally observed vibronic transitions of NO2 [J. Chem. Phys. 119, 5923 (2003)] to investigate the time domain nonadiabatic dynamics of this molecule on the coupled X2A1 and A2B2 electronic states, using both quantum mechanical and quasiclassical techniques. From the quantum mechanical point of view, we show that the transfer of population to the electronic ground state originating from a wave packet launched on the excited state occurs in a stepwise fashion. The evolution of wave packets launched on the electronic ground state is instead more complex because the crossing seam is located close to the bottom of the electronic excited state. We next use the mapping formalism, which replaces the discrete electronic degrees of freedom by continuous ones, to obtain a classical description of the coupled electronic states. We propagate gaussian swarms of trajectories to show that this approach can be used to calculate the populations in each electronic state. We finally propose a very simple trajectory surface hopping model, which assumes that trajectories have a constant probability to jump onto the other state in a particular region of the phase space and a null hopping probability outside from this region. Quasiclassical calculations show that this model enables a precise estimation of complex quantities, like for example the projection of the instantaneous probability density on given planes.Comment: accepted for publication in J. Chem. Phy

Socio-Emotional Competencies and School Performance in Adolescence: What Role for School Adjustment?

There is growing evidence in the literature of positive relationships between socio-emotional competencies and school performance. Several hypotheses have been used to explain how these variables may be related to school performance. In this paper, we explored the role of various school adjustment variables in the relationship between interpersonal socio-emotional competencies and school grades, using a weighted network approach. This network approach allowed us to analyze the structure of interrelations between each variable, pointing to both central and mediatory school and socio-emotional variables within the network. Self-reported data from around 3,400 French vocational high school students were examined. This data included a set of interpersonal socio-emotional competencies (cognitive and affective empathy, socio-emotional behaviors and collective orientation), school adjustment measures (adaptation to the institution, school anxiety, self-regulation at school, and self-perceived competence at school) as well as grades in mathematics and French language. The results showed that self-regulation at school weighted the most strongly on the whole network, and was the most important mediatory pathway. More specifically, self-regulation mediated the relationships between interpersonal socio-emotional competencies and school grades

Coherent Oscillatory Femtosecond Dynamics in Multichannel Photodynamics of NO2 Studied by Spatially Masked Electron Imaging

400 fs) a second slow (near 0 eV) photoelectron channel is observed that is associated with one photon excitation at 400 nm to the first excited (A) over bar B-2(2) state NO2 followed by two photon excitation at 266 nm leading to near threshould tomization and dissociation to NO- + O(P-3). Distinctive oscillatory patterns were found in the pump-probe transients of the photoelectron yield for both the slow and the fast photoelectron channels but with different periods of about 750 fs (slow) ro 590 fs (fast) Extensive polarization experiments are reported for both linerar and circular polarized pump and probe laser geometries. We discuss the oscillatory mechanism in relation to ab initio calculations of relevant Rydberg and valence type excited states of NO2 near 9.3 eV. We propose that an oscillating wavepacked of mixed Rydberg and valence character that predissociates is reponsible for the observed osicillations in the transients of the fast (0.88 eV) photoelectron channel