We here present a quantum chemical analysis of the possible Peierls distortions accompanying charge redistribution in the Pt-2(dta)(4)I infinite chain. Starting with the building block calculations, we point out the participation of the CH3CS2-(dta) ligand in the mechanism of electron transfer. As the chain grows, the position and the geometry of the equatorial dta ligands are significantly altered. These changes indirectly control the Pt-I distances and lead to noticeable reduction of electron-phonon coupling through bridging halogen. These results agree with experimental data suggesting the involvement of internal degrees of freedom in the electron trapping phenomenon.