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 nearest and the next nearest layers are taken into acount. Interactions can be noncompeting or competing. We find five different stable structures stable 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. Aditionally we find two structures, the structure with a primitive cell which extends over 2 smectic layers SmC*(2) and SmC*(4) the primitive cell cosists of 4 smectic layers.