To improve the design of molecular rectifiers, a molecule is presented for performing the digital XOR function where the output circuit is independent of the inputs. An intermolecular inelastic effect was optimised to get the non-linear effect for an XOR to work. This demonstrates how an intramolecular circuit can be designed where energy is provided along the molecule independently of the inputs. The electronic characteristics of this molecule-XOR were calculated using the N-ESQC technique for N = 4 interconnects at a semi-empirical level of description. Inside a single molecule, pilling up each classical function implemented by a specific chemical group (two rectifiers and a rotor for the XOR) is limited in the final molecule by the spectral mixing of the molecular orbitals of each function. (C) 2007 Elsevier B.V. All rights reserved.