LT-structural changes of the (NbSe4)10I3 compound, a quasi-one dimensional charge density wave system

In order to study the structural background of the giant thermal hysteresis observed in the thermopower measurements [1] of the CDW system (NbSe4)10I3, zeroth-order Weissenberg and oscillation photographs were taken at temperatures below Peierls transition. A reversible transformation of the room temperature tetragonal lattice into four symmetricaly equivalent monoclinic domains was observed with the monoclinic angle behaving like an order parameter