External doping of fullerenes C-60 and C-70 with heteroatoms is performed i
n a low pressure condensation cell, through the mixing of a vapor of doping
material with a vapor made of preformed fullerenes. Mass spectrometric inv
estigations of the resulting cluster distributions of C60Mx and C70Mx clust
ers are carried out for M = {Fe, Co, Ni, Rh, Ir and Si}. Further laser indu
ced photofragmentation of these C60Mx and C(70)M(x)precursor clusters leads
to the production of in-cage doped heterofullerenes with composition C59-2
nM and C69-2nM We complement our study with ab-initio calculations of the g
eometrical and electronic structure of C59Si and C58Si2, obtained within de
nsity functional theory by relaxing self-consistently the structures to the
local minima. (C) 1999 Acta Metallurgica Inc.