I have used ‘compute voronoi/atom’ to calculate the volume of a group befor.

Now I found the developers added som options for voronoi/atom command.

as I understand from ducumentation the suggestion for calculate the volume of a group is using only_group options. but I used this options and compared the result

with the older method, I found there is big diffrence and it is not ok. also the volume of

a group that calculated is constant during simulation. I put following the older and new commands. please advise me where I am wrong.



old commands:
compute vol all voronoi/atom
compute vol1 group_1 reduce sum c_vol[1]

new commands:
compute newvol group_1 voronoi/atom only_group
compute vol2 group_1 reduce sum c_newvol[1]


if you use only_group option, you split the simulation cell the same way as if there were atoms of that group only. So your "volume of a group" is in this case the volume of the cell, and thus it stays constant. To calculate the "volume of a group", you should still use just voronoi/atom without only_group keyword.


22.09.2013, 10:42, "mohammad sharif" <[email protected]>: