# Boundary conditions for triangular lattice in comsol

I am trying to simulate an infinite 2D triangular lattice in Comsol but I am confused that how should I use periodic floquet boundary conditions on the unit-cell. A unit cell that I am using is given below:

It has $$6$$ sides, $$L1,L2,...,L6$$. In the case of a square lattice, we simply just select floquet boundary conditions on both pairs of opposite sides because $$k_x$$ and $$k_y$$ are parallel to those sides.

Now, the pair of opposite sides (i.e. L1 and L4, L2 and L5, and L3 and L6) are not parallel to the $$k$$ vectors. How do we define boundary conditions now?

(I am trying to calculate the band structure on $$\Gamma$$, $$K$$ and $$M$$ points which are defined on this orthogonal $$k_x$$, $$k_y$$ axis.)