A qual. approach is developed in which one-dimensional energy bands can be approx. constructed via MO calcns. on dimers. The primary idea is based on the following two points. First, the energy bands could be considered as a result of interaction between repeated units (cells) of the system which exists either in corresponding dimer or in polymer. Second, the MOs of a dimer can be correlated to the crystal orbitals of a linear chain with the same structural unit both at the center and the edge of the first Brillouin zone. In LCAO-CO scheme, the one-dimensional crystal orbitals are both real at zone center and zone edge. Such kind of combination does not exist in a dimer because no translational symmetry is available. Every MO of a dimer could be formulated as a sum of in-phase and out-of-phase components where one of them would be dominant. This leads to the view that the mol. orbitals of a dimer result from crystal orbitals perturbed by termination such that the in-phase and out-of-phase characteristics are preserved. As a consequence, mol. orbitals of a dimer could be classified into pseudo-in-phase and pseudo-out-of-phase species, corresponding to those at zone center and zone edge in a linear chain, resp. Based on these assumptions, qual. band diagrams are easily constructed from dimer calcns., which in turn give useful information about linear polymers. As examples, the EH band structures of [Pt(CN)2-4]?(eclipsed) and polyacetlene (C2H2)?compared and discussed in detail with those constructed from [Pt(CN)2-4]2 (eclipsed) and C4H6. They are quite consistent with each other.8

Key words: DIMER, CRYSTAL STRUCTURE, PLATINUM COMPLEX, GOLD COMPLEX, ENERGY LEVELS, SULFIDE COMPLEX, CYANO COMPLEX, PHOSPHORUS COMPLEX, LONG CHAIN COMPOUND, CONDUCTIVE MATERIALS