▁patterns ▁cannot ▁be ▁considered ▁purely ▁kin emat ical ▁in ▁general . ▁There ▁are ▁models ▁that ▁attempt ▁to ▁introduce ▁corre ctions ▁to ▁convert ▁measured ▁P ED ▁patterns ▁into ▁true ▁kin emat ical ▁patterns ▁that ▁can ▁be ▁used ▁for ▁more ▁accurate ▁direct ▁methods ▁calculations , ▁with ▁varying ▁degrees ▁of ▁success . ▁Here , ▁the ▁most ▁basic ▁corre ctions ▁are ▁discussed . ▁In ▁purely ▁kin emat ical ▁diff raction , ▁the ▁intens ities ▁of ▁various ▁ ▁ref lections , ▁, ▁are ▁related ▁to ▁the ▁square ▁of ▁the ▁amplitude ▁of ▁the ▁structure ▁factor , ▁ ▁by ▁the ▁equation : ▁ ▁This ▁relationship ▁is ▁generally ▁far ▁from ▁accurate ▁for ▁experimental ▁dynam ical ▁electron ▁diff raction ▁and ▁when ▁many ▁ref lections ▁have ▁a ▁large ▁exc itation ▁error . ▁First , ▁a ▁Lor ent z ▁correction ▁analog ous ▁to ▁that ▁used ▁in ▁x - ray ▁diff raction ▁can ▁be ▁applied ▁to ▁account ▁for ▁the ▁fact ▁that ▁ref lections ▁are ▁inf re qu ently ▁exactly ▁at ▁the ▁B rag g ▁condition ▁over ▁the ▁course ▁of ▁a ▁P ED ▁measurement . ▁This ▁geomet rical ▁correction ▁factor ▁can ▁be ▁shown ▁to ▁assume ▁the ▁approximate ▁form : ▁ ▁where ▁g ▁is ▁the ▁reci pro cal ▁space ▁magnitude ▁of ▁the ▁reflection ▁in ▁question ▁and ▁Ro ▁is ▁the ▁radius ▁of ▁the ▁La ue ▁circle , ▁usually ▁taken ▁to ▁be ▁equal ▁to ▁ φ . ▁While ▁this ▁correction ▁accounts ▁for ▁the ▁integration ▁over ▁the ▁exc itation ▁error , ▁it ▁takes ▁no ▁account ▁for ▁the ▁dynam ical ▁effects ▁that ▁are ▁ever - present ▁in ▁electron ▁diff raction .