d50 value u201d and u201c mass median diameter u201d or mmd can be used interchangeably and denote the average particle size by mass i e the average equivalent diameter of a particle which is defined as the diameter where 50 w of the particles of the ensemble have a larger equivalent spherical diameter and the other 50 w have a smaller equivalent spherical diameter the term u201c amorphous form u201d denotes a solid material which does not possess a distinguishable crystal lattice and the molecular arrangement of molecules lacks a long range order in particular amorphous denotes a material that does not show a sharp bragg diffraction peak bragg 39 s law describes the diffraction of crystalline material with the equation u201c 2d u00b7 sin theta n u00b7 lambda u201d wherein u201c d u201d denotes perpendicular distance in angstroms between pairs of adjacent planes in a crystal u201c d spacing u201d u201c theta u201d denotes the bragg angle u201c lambda u201d denotes the wavelength and u201c n u201d is an integer when bragg 39 s law is fulfilled the reflected beams are in phase and interfere constructively so that bragg diffraction peaks are observed in the x ray diffraction pattern at angles of incidence other than the bragg angle reflected beams are out of phase and destructive interference or cancellation occurs amorphous material does not satisfy bragg 39 s law and no sharp bragg diffraction peaks are observed in the x ray diffraction pattern the xrpd pattern of an amorphous material is further characterized by one or more amorphous halos the term u201c inclusion complex u201d denotes a stoichiometric multicomponent complex in contrast to salts no or only partial proton transfer is expected in inclusion complexes an inclusion complex can be an amorphous form.