Possible stable structures of chiral polar smectics with significant interactions between next nearest layers

We analyse stable structures in the model where interactions between the ne arest and the next nearest layers are taken into acount. Interactions can b e noncompeting or competing. We find five different stable structures stabl e at different values of model parameters. Three of them are already known: the ferroelectric SmC*, the antiferroelectric SmC*(A) phase and by recent experiments confirmed helicoidal shea-pitch SmC*(alpha) structure. Aditiona lly we find two structures, the structure with a primitive cell which exten ds over 2 smectic layers SmC*(2) and SmC*(4) the primitive cell cosists of 4 smectic layers.