There is considerable interest in metal-carbon clusters because of the
possible applications of metal-carbon cluster to catalytic and new el
ectronic materials, pollution control, chemical tracers, superconducti
ve materials and in site-specific protein chemistry. In recent years,
studies have especially focused on transition-metal carbon clusters. I
n this paper, quantum chemical ab initio method is used to study the g
eometric and electronic structures of the Mo2C8, cluster. In trying to
determine likely candidates for the structure of ground state of Mo2C
8, a number of possible isomeric structures were investigated. The mos
t stable structure is found to possess C-2h symmetry, where two Mo ato
ms connect directly each other and each Mo atom connects to four carbo
n atoms, Mo atom is enclosed by C atoms, so as the spatial effect and
bond forming property are concerned, the reactions of Mo2C8- with NH3,
H2O are difficult, In fact, experiment had observed Mo2C8- ion are in
deed completely unreactive with NH3 and H2O. Furthermore, our calculat
ed E(A) of this isomer is 3.6 eV, which is just the upper limit of the
experimental value(the experimental value of E(A)(MO(2)C(8)) is betwe
en 2.7 +/- 0.2 eV and 3.3 +/- 0.3 eV), and this structure can also exp
lain other existing experimental results perfectly.