The electronic structures and properties of metallocene I [eta5 - C5H5)MoX (CO)2[C(CH2)2CH2O] | (X:Cl,Br,I) has been calculated by means of G98W package and taking Lanl2dz basis set. The stabilities of the complexes,some of frontier molecular orbital energies, the populations of the atomic net charges in these complexes and the composition characteristics of some frontier molecular orbitals have been investigated .The results show that the structure units of the title complexes are energetically stable and they may exist as building blocks. Some results obtained may be useful as references for...