[lammps-users] Is there the way to create particles randomly consecutively?

Dear All,

I want to simulate interaction of oxygen molecule and water molecule with Silicon surface. To do so, I create a water molecule/oxygen molecule just above silicon surface. For long time kinetic I should create many water/O2 molecule randomly and consecutively.

First,I tried to use “displace_atoms” command, following command “create”, with argument “random”, but it turns out to move each atom of molecule not move molecule it self. While with argument “move”, it move the molecule but not randomly. Both command also produce what I did not expect , the particles which move are not the newest particle which is just created rather other older particles.

–part of my input file------------------------------------------------------------------------------
variable b loop 50

part of my input file like this:
create_atoms 1 single 9.435 9.435 26.00 units box
create_atoms 9 single 10.192225 9.435 25.413166 units box
create_atoms 10 single 8.677774 9.435 25.413166 units box

group g_oxyfirst$b type 1
group g_H1first$b type 9
group g_H2first$b type 10

group waterfirst$b union g_oxyfirst$b g_H1first$b g_H2first$b
displace_atoms waterfirst$b move 5 5 0 units box