I would like to deposit atoms on a substrate from a distance h=70 , I used this command fix 8 g_depo deposit 3000 3 2000 70546 region r_adatom local 70 72 1.0 vz -6.9 -6.9 units box , but I see that some atoms are at a distance greater than 70( =86).
I will be appreciate it if anyone can give me a suggestion.
Best regard

distance h from where?

so how is this region defined?

This is contradicting your requirement. With this setting any atom that is within a z-distance of 1.0 length unit will be displaced by 70-72 length units in addition to the “near” local atom.

It looks like fix deposit is doing exactly what you are asking for.

I would like to deposit atoms on a substrate from a distance h=70 above the surface interface in Z.The region :region r_adatom block 0.0 46.65 0.0 80.8 29 109 side in. This my input file (2.7 KB)

Then you should obviously use the “global” keyword, not “local”, and choose the dimensions of the deposit region accordingly. This is really mostly a matter of carefully reading the documentation and acting accordingly.

I did that but i have error in first step ERROR: Lost atoms: original 10802 current 10801

So you need to figure out why this happens. There are plenty of previous discussions on that topic.

You are trying to do a complex simulation so to get it working you have to check for complex issues. There is not likely a single command or fix that will (magically) solve all issues. You need to debug your input piece by piece and step by step. Nobody will do this for you since this is your research and your work.