This paper introduces a systematic procedure to obtain well-relaxed atomistic melt structures from mesocale models of vinyl polymers based on sequences of diads. Following the methodology introduced by Milano and Müller-Plathe [J. Phys. Chem. B. 2005, 109, 18609], coarse-grain models consisting of sequences of superatoms of two different types meso and racemo have been used to relax mesocale melts of atactic and syndiotactic polystyrene. The proposed method, based on a fully geometrical approach, does not involve expensive potential energy and force evaluations and allows a very fast and efficient reconstruction of the atomistic detail. The method, successfully tested against experimental data, allows us to obtain all atom models of both stereoregular and stereoirregular polymers and opens the possibility of relaxing large molecular weight melts of vinyl chains.