Dear Jacob, 

>Also, resolution would depend a lot on phase accuracy/precision, no? 

I feel that there is a traditional confusing between the terms, which 
"resolution" you are talking about since this term is over-used: 

- resolution of a particular map (then it may be local or a kind of an overall 
resolution); also, which "features" you want to see as separated ? 
- formal resolution CUT-OFF (and not a "resolution") of a corresponding set of 
reflections ; 
- effective resolution CUT-OFF of a set of reflections (say, if the highest 
resolution shell is incomplete, what we consider as such a resolution?) 
- ... 

Differences between them and some relations are (yet not exhaustively) 
addressed in Urzhumtseva et al. (2013) Acta Cryst., D69 , 1921-1934 . 

Is it what you want to know : 
- at which resolution cut-off a map calculated with a corresponding complete 
data set with exact phases can show two atoms (with which B?) as separate peaks 
? 

If you want a more "rule of thumbs"-kind answer, there was a discussion about 
the "Sheldrick's rule" (works by Sheldrick and by Bricogne's teams); I think 
traditionally the corresponding limit was considered as such an atomic 
resolution (CUT-OFF). 

Otherwise, as it was said in several previous comments, everybody has his own 
idea what is a "high resolution" and what is a "low resolution" (even more 
disagreement on this :-) ). 

Best regards, 

Sacha Urzhumtsev 

----- Le 11 Jan 18, à 21:31, Keller, Jacob <[email protected]> a écrit : 

>>I tell people it is when your resolution is less than the bond length that
> >connects the two atoms.

> I thought this was sort of a pitfall, since the Bragg spacings don't 
> necessarily
> map on to conventional resolution. But it would fit the 1.5 Ang estimate.

> Also, resolution would depend a lot on phase accuracy/precision, no?

> JPK

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