If you have a mathematical model for creating such surfaces (i.e. diamond square algorithm), you could write a small script that will loop through all atom positions and delete all atoms above/below the generated surface.
You would have to be careful though, because cutting a surface like that may introduce a lot of problems (unstable surface, loose bonds etc), which will give bad simulation results unless handled properly.
You can also look at the create_atoms command and its var/set keywords. The
doc page has a picture of a sinusoidal surface created with a simple formula via
the variable command.
You could use the same idea to create a more “random” surface if you
were creative about the formula you defined - there is a also a random() function
available in the variable command.
Basically that command is doing what Anders suggested, it is generating
lots of atoms and discarding some by figuring out if they are above or below
the analytic surface.
I have made a smooth surface(several layers) and wrote a script too loop all the atom positions.
However, the most challenge technique is to define a formula to delete the atoms randomly.
Do you have any suggestions about this?
Thank you.
Best Wishes
Liyi
Anders Hafreager <andershaf@…24…> 于2018年11月30日周五 下午10:16写道：