Specifying a radially symmetric E-Field

Hi all,

I am a newbie in LAMMPS and I’m trying to simulate the dynamics of a droplet (2000 molecules) on a substrate (having properties of Silicon) when a radial electric field centered at the water droplet’s center of mass is applied (NVT ensemble @ 300K). I am not getting the desired symmetric behavior on using the fix efield LAMMPS command to spatially define the field using an atom style variable.

(I’m using the latest version of LAMMPS)

I would really appreciate if someone could highlight where I’m going wrong.

Relevant Portion of Code-

Hi all,

I am a newbie in LAMMPS and I’m trying to simulate the dynamics of a droplet (2000 molecules) on a substrate (having properties of Silicon) when a radial electric field centered at the water droplet’s center of mass is applied (NVT ensemble @ 300K). I am not getting the desired symmetric behavior on using the fix efield LAMMPS command to spatially define the field using an atom style variable.

what do you mean by this? how “symmetric” is your expected “symmetric”? and how do you determine you are not getting the expected behavior. are you accounting for the fact, that there are other influences affecting your trajectory than the electrical field and that you would have to have a ridiculously large (so large that your water molecules would evaporate instantly) to have molecules follow a straight path determined by the electrical field. for realistic field strengths, you should just see a small bias compared to a system without the field.

(I’m using the latest version of LAMMPS)

this is useless information, since what is the latest version of LAMMPS keeps changing all the time. LAMMPS prints the version date at the beginning of its output. this is the proper information about the version.

I would really appreciate if someone could highlight where I’m going wrong.

my guess is that you are wrongly expecting macroscopic behavior on a microscopic setup.

axel.