Born--Oppenheimer dynamics using density-functional theory: Equilibrium and fragmentation of small sodium clusters
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (US)
The properties of small neutral and positively charged sodium clusters and the fragmentation dynamics of Na{sup ++}{sub 4} are investigated using a simulation technique which combines classical molecular dynamics on the electronic Born--Oppenheimer ground-state potential surface with electronic structure calculations via the local spin-density functional method. Results for the optimal energies and structures of Na{sub {ital n}} and Na{sup +}{sub {ital n}} ({ital n}{le}4) are in quantitative agreement with previous studies and experimental data. Fission of Na{sup ++}{sub 4} on its ground state Born--Oppenheimer potential-energy surface, following sudden ionization of selected configurations of an Na{sup +}{sub 4} (or Na{sub 4}) cluster, whose vibrational energy content corresponds to 300 K, is found to occur on a picosecond time scale. The preferred fission channel is found to be Na{sup +}{sub 3}+Na{sup +}, with an interfragment relative translational kinetic energy of {similar to}2 eV, and a vibrationally excited Na{sup +}{sub 3}. The dynamics of the fragmentation process is analyzed.
- DOE Contract Number:
- FG05-86ER45234
- OSTI ID:
- 6145668
- Journal Information:
- Journal of Chemical Physics; (USA), Vol. 94:1; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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