Dear Lammps users, I a trying to understand what happens during the pullout of the soft EPDM nanofiber form matrix. So, I created two different samples: (a) one is with pristine nanofiber (only vdW at the interface) and (b) the other one is with surface modified nanofiber (chemical bonds at the interface). See figures a and b in the below image. During the pull-out test via fix s…

Hi. I have a quick question about potentials and system size for simulating a (short - 20-30 base pairs) DNA fragment on a Au nanoparticle. Assuming that the Au nanoparticle is approximated by a Au slab, is it realistic to expect LAMMPS to be able to give reasonable answers? I am coming from an ab-initio background and I have not used LAMMPS before. I am asking for a colleague t…

Dear LAMMPS users, I want to calculate interaction forces between many groups. And each group consists of several atoms. The simulation box is assigned with periodic boundary condition in each dimension, and the pair_syle is the lj/cut/coul/long (kspace_style pppm). The problem is that the number of goups is around 80, which indicate the code “compute group/group” is not applica…

Hi, Axel The simulated system consists of a flat slab and a water droplet, and is designed to obtain the contact angle. What I want is the force distribution of the slab, which requires the interaction forces between the water droplet and slab atoms at given positions. The data is averaged over 2ns with an interval of 1ps. Jianbo Wang 1 post - 1 participant …

Thanks very much for your help. I will try to address the problem following your kind suggestions. Best regards Jianbo Wang 1 post - 1 participant Read full topic

Dear lammps users, Hello, I have a question about the effects of damping parameter in nvt command. When we use “fix nvt” to control temperature, we can make fix ID all nvt temp (T_ini) (T_fin) (t_damp) , where t_damp is the temperature damping parameter. I know that this parameter is the timescale of thermal evolution. When t_damp is small, the thermal evolution is fast. (Is…

Dear LAMMPS users, I tried to ramp up stresses, normal stress sigma_yy and sigma_zz, of my system using NPT. From my first run, the stress curves showed that the stress components are constant, i.e. they didn’t change with time after roughly 130 ps. However, the plateau of stress was not my target stress. For some reason, I restarted my simulation with exactly the same given stres…