On Wed, 6 Jul 2016 09:13:22 +0100, Randy Read <[log in to unmask]> wrote:
>Dear Zbyszek,
>
>I agree completely with your general point that there is a trend for an increasing number of people to adopt too-low symmetry, rewarded by lower R-factors in twinned refinement.
Dear Randy,
I wish you had not used the word "rewarded" - for Germans at least, it has no ironic or pejorative connotation. I hope people do not understand this as if you were endorsing this unfortunate practice. There are already too many structures being twin-refined "because it reduces the R-factors" (and I fell into this trap as well before reading Garib N. Murshudov (2011) "Some properties of crystallographic reliability index - Rfactor: effect of twinning" Appl. Comput. Math., V.10, N.2, 2011, pp.250-261 http://www.ysbl.york.ac.uk/refmac/papers/Rfactor.pdf ).
best,
Kay
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