  The frustration phenomenon in an exactly solvable spin-electron planar model
constituted by identical bipyramidal plaquettes is discussed within the
Toulouse's and dos Santos and Lyra's frustration concepts. It is shown that the
ground state of the model contains the unfrustrated spontaneously ordered
quantum ferromagnetic phase with local chiral degrees of freedom in the
electron sub-lattice and the disordered quantum one, where both the Ising and
electron sub-lattices are frustrated. The frustration of the latter sub-lattice
persists at finite temperatures, but only in the disordered region. It finally
vanishes at a certain frustration temperature. The reentrant behaviour of the
frustration in the electron sub-lattice with three consecutive frustration
temperatures due to a competition with the unfrustrated ferromagnetic spin
arrangement near the ground-state phase transition can also be observed.
