“…In most studies two-dimensional PSDs and PBEs have been used (Briesen, 2006;Ma et al, 2002;Oullion et al, 2007a,b;Puel et al, 1997Puel et al, , 2003a, the main reason being the difficulty of measuring particle size and growth in multiple directions, especially in situ during growth, as well as the computational difficulties commonly encountered in solving multi-dimensional PBEs. In the 2-D PSD case a crystal is typically described as a 3-D parallelepiped, with length L 1 , height L 2 and width L 3 , where one geometrical constraint is imposed to reduce the number of independent descriptors to two, e.g.…”