The incommensurate structure with an unusual diffraction pattern in a rapidly solidified V₆Ni₁₆Si₇ alloy is analysed and its reciprocal 'lattice' indexed using 18 basis vectors. This structure has some unique features, which are closely related to both conventional incommensurately modulated structures and quasi-crystals. However, it appears to differ from the latter two types of aperiodic structures in some important aspects.