Low temperature structural properties of the (TMTSF)2NO3 salt

The ordering of the anion in the molecular conductor salt (TMTSF) 2 NO 3 at low temperature depends on the rate of cooling and corresponds to the doubling of the a cell parameter. This order-disorder transition does not affect the crystal packing as the TMTSF chains in the ordered and in the disordered crystal structures at 12K can not be distinguished. This salt is strongly 1D at low temperature.