In defense of redundancy: While the IUCr online dictionary is notably silent about multiplicity, the term itself seems already oversubscribed and used differently in various crystallographic contexts.
(i) Each general or special position in a crystal structure has a certain multiplicity, defined by symmetry. (ii) General reflection multiplicity M is usually is defined by reflection symmetry, and when reflections are affected by special operations, the resulting corresponding lower multiplicity because they map onto themselves is accounted for in the epsilon factor e. Btw a useful table of M and e is Iwasaki & Ito Acta Cryst. (1977). A33, 227-229 (iii) In case of Laue patterns, overlap of higher order reflections is also called Multiplicity afaik (various Helliwell/Moffat et al papers explain this). So expanding the term multiplicity to include multiple instances of measurements of the same reflections - while admittedly avoiding the connotation of obsolescence - adds to its promiscuous meaning, where context becomes part of the definition.... I abstain from making any suggestions because in the past this has led to interesting but time-consuming philosophical discourse, proving in general the multiplicity of my reflections and positions redundant if not obsolete. Best, BR -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Kay Diederichs Sent: Sonntag, 18. Januar 2015 09:28 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Redundancy vs no of frames Dear Rohit Kumar, I prefer the term "multiplicity" instead of "redundancy" because the latter has a connotation of "not really needed any more". The relation then is multiplicity = c * number_of_frames * oscillation_range where the constant c depends mainly on the space group. HTH, Kay On Sun, 18 Jan 2015 02:35:46 +0530, rohit kumar <rohit...@gmail.com> wrote: >Dear all, > >Can anyone tell me how to calculate number of frames from redundancy or >vica versa > >Thank you >
