Using DFT modeling, we analyze the concerted action of gold atoms and dispersion interactions in cross-linked polyethylene. Our model consists of two oligomer chains (PEn) with 7, 11, 15, 19, or 23 carbon atoms in each oligomer cross-linked with one to three Au atoms through C-Au-C bonds. In structures with a single gold atom the C-Au-C bond is located in the central position of the oligomer. Binding energies (BEs) with respect to two oligomer radical fragments and Au are as high as 362-489 kJ/mol depending on the length of the oligomer chain When the dispersion contribution in PEn Au PEn oligomers is omitted, BE is almost independent of the number of carbon atoms, lying between 293 and 296 kJ/mol. The dispersion energy contributions to BEs in PEn Au PEn rise nearly linearly with the number of carbon atoms in the PEn chain. The carbon carbon distance in the C-Au-C moiety is around 4.1 angstrom, similar to the bond distance between saturated closed shell chains in the polyethylene crystal. BEs of pure saturated closed shell PEn PEn oligomers are 51-187 kJ/mol. Both Au atoms and dispersion interactions contribute considerably to the creation of nearly parallel chains of oligomers with reasonably high binding energies.