Structures of Al(n), its anions and cations up to n = 34: a theoretical investigation.
A systematic density functional study has been performed for neutral and singly charged clusters of aluminum with up to 34 atoms. A thorough search for global minimum structures has been carried out for Al(n) employing genetic algorithm and basin-hopping procedures. For Al(n) this confirms results of previous investigations up to n=22; new global minima have been located for n=23-31, 33. Structures for singly charged cations and anions have been obtained by reoptimization of the pool of 40 low-energy structures of the neutral clusters. The global minima of charged and neutral clusters are always low-spin states with the possible exception of a triplet state of Al(28), which is isoenergetic with a singlet. The cluster structures are mostly quite irregular and do not resemble fractions of the fcc bulk phase. High symmetries are found only for the global minimum of Al(23) and the triplet state of Al(28).
Drebov
Nedko
N
Institut für Physikalische Chemie, Karlsruher Institut fürTechnologie, Kaiserstrasse 12, Karlsruhe 76131, Germany.
Ahlrichs
Reinhart
R