On the interatomic electronic processes following Auger decay in neon dimer

Abstract

The accessible relaxation channels of the electronic states of Ne(++)-Ne and Ne(3+)-Ne populated by KLL Auger decay are studied. In particular, we address the "direct" and "exchange" interatomic Coulombic decays (ICDs) and the electron-transfer-mediated decay following the population of one-site states Ne(++)(2s(-2))-Ne and Ne(++)(2s(-1)2p(-1) (1)P)-Ne. Radiative charge transfer of the low lying Ne(++)(2p(-2))-Ne states, three-electron ICD process from the Ne(++)(2s(-2))-Ne states, as well as charge transfer at the points of curve crossing of the lowest in energy Ne(3+)(2p(-3))-Ne states are also discussed. To carry out the present study, we have calculated the potential energy curves (from 1.75 to 5.00 A) of the ground state Ne(2), the core ionized state Ne(+)(1s(-1))-Ne, and the dicationic and tricationic states with energies in the range of 45-140 eV using accurate ab initio methods and basis sets. Apart from being of interest by themselves, the results obtained may be helpful in interpreting the recent measurements of interatomic electronic processes following Auger decay in neon dimer [K. Kreidi et al., J. Phys. B 41, 101002 (2008)].

Dependence of interatomic decay widths on the symmetry of the decaying state: Analytical expressions andab initioresults

“…(14) and (16). The line strength S (A) i (E A L A ; E A L A ) and transition energies ω i correspond to the deexcitation of the initial state in the case of ETI or pRICD or to the transition between the outer-and inner-valence shells in the case of sRICD.…”

“…Originally ICD was predicted [1] and investigated both theoretically and experimentally [2][3][4][5][6][7] in singly ionized clusters, where one of the constituent monomers had a hole in an inner-valence shell. Later investigations showed that it exists also in excited neutral clusters [8][9][10][11] and in excited doubly ionized clusters that are produced via an Auger decay on one of the monomers [12][13][14][15][16][17]. Thus, there seems to be no restrictions on the nature of the initially excited state and interatomic decay takes place as long as the corresponding channel is energetically accessible.…”

Enhanced production of low energy electrons by alpha particle impact

“…Firstly, Ne 2 has been already subject to many experimental and theoretical studies of ICD (4,(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) and thus can be regarded as a well known model system for the ICD process. Secondly, it allows us-due to our experimental technique-to directly compare the change in electron emission between an isolated gas phase atom with one that is embedded in an environment: The dimer consists of a neon atom that is surrounded by a single second atom bound only by the van der Waals force (3 meV or 0.07 kcal∕mol).…”

Collective relaxation processes in atoms, molecules and clusters

“…A similar collective ICD transition of two inner-valence vacancies localized on a single atom is possible in Ne 2 following single-site double Ne 2s ionization [100] and in NeAr dimers after double Ar 3s ionization [101]. The three-electron decay…”