On 17/03/17 14:41, Xiao Lei wrote:
>
> In Coot, I could adjust the densities of map (2Fo-Fc in my case)
> radius, but I'd like to show the density on selective residues, not
> on the unselected part of structure, is there a way to do it?

Yes.  Extensions -> Maps -> Mask Map by Atom Selection...

After selecting your  model molecule, you will be asked about an Atom Selection

use (for example)

//A/20-30

to mean residues 20 to 30 (inclusive) in the A chain.

You will want to click the "Invert Masking" checkbutton.

Masked maps often scroll "slowly" so increase (say to 0.5) the r.m.s.d. step in the Map Properties.

Paul.