ON THE POSSIBILITY OF SMALL Mn CLUSTERS HAVING CUBIC SYMMETRY AND THEIR MAGNETIC MOMENTS

Possibility of cubic structures in small manganese (Mn) clusters has been studied using the linear combination of Gaussian orbitals (LCGO) method. Local spin density approximation is adopted for the exchange correlation potential. Both high-spin and low-spin states are found for Mn13 and Mn19 clusters with the face-centered cubic symmetry; however, no equilibrium lattice constant could be found. For Mn9 and Mn15 clusters with the body-centered cubic symmetry, only high-spin states are found. No equilibrium lattice constant could be found for bcc Mn9; however, a weak possibility of bcc structure in Mn15 is found. The calculated magnetic moment of Mn15 is, however, found to be too large compared with the experimental result.