Fragmentation of Si clusters studied by a dynamical Hartree-Fock method at semi-empirical level

摘要

This study describes fragmentation of silicon clusters of size N ≤ 40. Fragmentation is produced by the increase of the kinetic energy E_k of the nuclear system and a time-dependent Hartree-Fock method, with a semi-empirical Hamiltonian is used for the evaluation of the transient ensuing the energy input. A typical channel of fragmentation has been observed which consists on the emission of small (from 1 to 5) groups of atoms. Due to these losses, the fragmentation remnants for N ≥ 20 reach a size equal to 1/2- 1/4 of the original one. These trends are in agreement with the experimental ones. Furthermore the critical energies obtained from fragmentation calculations are discussed in the light of the binding energies evaluated for the stationary state.