Thanks all - also for jogging my memory.
Peter, I think Garib ended up doing something statistically
sophisticated, but I couldn't track down the slides or documentation I
remember seeing somewhere. But I didn't dig very hard, and if it's been
there since 2012, then that explains why I
I am not quite sure how it is done in Refmac, but in phenix it works as
follows
- difference maps are gradient maps for a least squares target and they do
not contain any amplitude contamination from twinning.
- Fo type maps are computed either via classic detwinning (solving the
linear
Yes, they are "de-twinned". There is really no other way to do it.
Without de-twinning you'd be looking at a map of two overlapping
structures. How do you turn a single observation of the sum of
intensities from two different hkls into two different Iobs values? You
need to know the ratio.
Yes - the “Fobs” is extracted from the twinned ”Iobs”
Which is actually I1 + I2*twin_factor , and yes, how to do that properly is
tricky.
On Tue, 28 Apr 2020 at 22:20, Frank von Delft
wrote:
> Hi all - feel free to point me to the docs if it's already clear somewhere:
>
> When refmac generates
Hi all - feel free to point me to the docs if it's already clear somewhere:
When refmac generates 2mFo-DFc maps after twinned refinement, are they
the "untwinned" view of the electron density? I.e. with the twinnig
convoluted out by his statistical magic?
I remember Garib mentioning the
