I will discuss the holographic model which develops spontaneous inhomogeneous structure on top of the explicit translational symmetry breaking lattice. In case of inhomogeneous (periodic) symmetry breaking patterns the system demonstrates the physics of commensurate lock in: provided the wave-lengths of the two structures are close to each other, the spontaneous structure "locks in" and assumes the periodicity of the lattice. This commensurate state may be understood as a holographic version of the Mott insulator. When the wave-lengths are sufficiently different, the system may assume incommensurate state, when two periods are not simply related. Then, provided the lattice is strong enough, the mismatch is accounted for by a soliton on top of the commensurate state -- a discommensuration. I will outline the features of the commensurate state, its thermodynamic stability the role of discommensurations and the corresponding incommensurate states.
