We calculated ionization potentials (IPs) to create single core-hole states and double ionization potentials (DIPs) to create double core-hole (DCH) states for a series of trihalosilyl-trimethylsilyl molecules bridged with hydrocarbons. From the calculated DIPs, IPs, and the hole-hole repulsion energies, we extracted the excess relaxation energies for the creation of DCHs at a single atomic site and interatomic relaxation energies for the creation of DCHs at two different sites. These excess and interatomic relaxation energies depend solely on the chemical environment around the atom(s) with core hole(s). We found that the interatomic relaxation is almost blocked by a dimethylene group (-CH(2)CH(2)-). (C) 2011 Elsevier B.V. All rights reserved.