Well according to Google this paper (JCS, 1936) contains the phrase "magnitudes of the structure amplitude factors (F)":
http://www.google.co.uk/search?hl=en&q=%22magnitudes+of+the+structure+am plitude+factors%22&btnG=Search&meta= . It seems that "structure amplitude factor" is what we have now abbreviated to "structure factor", i.e. it would appear that "amplitude" was being used in a different sense from what we are using. Logically the magnitude of a structure amplitude factor should be a "structure amplitude factor magnitude", so I guess it was not surprising that it was abbreviated to just "structure amplitude". I hardly think you could call it a "structure amplitude factor amplitude"! -- Ian > -----Original Message----- > From: owner-ccp...@jiscmail.ac.uk > [mailto:owner-ccp...@jiscmail.ac.uk] On Behalf Of Bernhard Rupp > Sent: 12 January 2009 17:44 > To: CCP4BB@JISCMAIL.AC.UK; sa...@igbmc.fr > Subject: Re: [ccp4bb] structure (factor) amplitude > > Hmmm..... > > Sacha just threw another wrench into that discourse. Seems we are > also faced with a duality problem here: > > Coming from a mathematical point of view treating F as a > complex number, > > structure factor magnitude or > structure factor modulus > > is more logical and more direct. > > If you are taking the physical pov (let's not go into detail > there, btw) > *interpreting* the complex number as wave description > (and here I must say Ian's point wrt song title/name is well taken) > > structure factor amplitude > > is more logical. > > Best, BR > > Dear Bernhard, > > First of all, happy new year ! > > > I am getting conflicting comments on the use of > > 'structure factor amplitude' > > vs. just > > 'structure amplitude' for |F|. > > Even when "structure factor amplitude" (or "magnitude", > following some > english-speaking persons?? If I am right I learned that > M.Woolfson prefers > "magnitude". My English is too poor to judge) seems to be > long, it seems to > be correct and have a clear meaning. That is not the case for > "structure > amplitude". In that sens I agree with Ethan and Pavel. > > With best wishes ! > > Sacha > > Disclaimer This communication is confidential and may contain privileged information intended solely for the named addressee(s). It may not be used or disclosed except for the purpose for which it has been sent. If you are not the intended recipient you must not review, use, disclose, copy, distribute or take any action in reliance upon it. If you have received this communication in error, please notify Astex Therapeutics Ltd by emailing i.tic...@astex-therapeutics.com and destroy all copies of the message and any attached documents. Astex Therapeutics Ltd monitors, controls and protects all its messaging traffic in compliance with its corporate email policy. The Company accepts no liability or responsibility for any onward transmission or use of emails and attachments having left the Astex Therapeutics domain. Unless expressly stated, opinions in this message are those of the individual sender and not of Astex Therapeutics Ltd. The recipient should check this email and any attachments for the presence of computer viruses. Astex Therapeutics Ltd accepts no liability for damage caused by any virus transmitted by this email. E-mail is susceptible to data corruption, interception, unauthorized amendment, and tampering, Astex Therapeutics Ltd only send and receive e-mails on the basis that the Company is not liable for any such alteration or any consequences thereof. Astex Therapeutics Ltd., Registered in England at 436 Cambridge Science Park, Cambridge CB4 0QA under number 3751674
