where the superscript specifies the number of electrons in the subsystem, with the integer N I and a fractional charge 0 ≤ q ≤ 1. Note that is scheme is inspired by Wasserman's partition DFT , but treats the NAXC using a a conventional GGA functional. For the prototypical tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) complex, it could be demonstrated that such an approach leads to a correct description of the intermolecular charge transfer induced by an electric field.