Institut des Sciences Moléculaires d'Orsay



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Accueil > Séminaires > Année 2010 > Séminaire Viktoria Ivanovskaya ( 19 janvier 2010 )

Séminaire Viktoria Ivanovskaya ( 19 janvier 2010 )

Laboratoire des Collisions Atomiques et Moléculaires, Orsay

How can simple molecules, in particular the most abundant H2 molecule, form in the
interstellar space considering that even in the densest interstellar clouds atoms are too spread out ? It has been proposed that molecular hydrogen may be formed on
carbonaceous surfaces of dust particles. Due to the low temperatures of interstellar
media, to be viable the discussed process should have no, or very little, barrier.
In this presentation I will discuss the results of DFT simulations of atomic H
chemisorption onto different graphitic like surfaces. First, I will analyze the hydrogen
interaction with perfect graphene. Beyond several earlier works on this topic, I will
focus on some new key points which have not been discussed so far. Then, I will
propose a new point of view on which topological defects play a key role for
molecular catalysis at dust grains. In that case DFT-NEB calculations will be used to
find out the reaction path and the associated reaction barriers.

Affiche V.Ivanovskaya 2010 - 137.9 ko