LIGGGHTS® - User Forum

Hi,

I use the compute multi-sphere command to calculate body position, and later I would like to exert a force on each multi-sphere body depends on their position in vertical space(z direction). This used to work for me in only sphere system. For the multi-sphere system,I use similar syntax like following

compute zp all multisphere property xcm
variable prs atom -20.*c_zp[3]
fix pressure crystal setforce 0.0 0.0 v_prs

hello!

I am trying to see the interaction between a structure and particles by using an external coupling with LIGGGHTS. I modeled a structure by using mesh model. So with move/mesh function, I would like to update the mesh's position and velocity from my code and receive the forces applied by particles to my code.

Is it available for LIGGGHTS to read the position and velocity from variables out of the program?
This option of "linear/variable args" seems to be suitable, but still, don't know how to feed those variables in the input file.

Hi,

I'm starting to play around liggghts library functions (/src/library.cpp) inside my fortran code.

My doubt is whether can I pass a different number of arguments (natoms) in lammps_scatter_atoms than I've got in lammps_scatter_atoms.

To clarify, I'll be handling the collisions in LIGGGHTS and the rest in my code. Is it possible to make the particles inlet inside my code or this has to made in the LIGGGHTS directly?

Thanks in advance.

Hi all, I am trying to set up a simulation where particles are inserted in an extreme of a rectangular pipe. Then, a movile surface should compress the particles (along the z axis). The sript (attached here) runs but few steps later the following error comes up:

ERROR: Mesh (id servo): Mesh elements have been lost / left the domain. Please use 'boundary m m m' or scale/translate/rotate the mesh or change its dynamics (../multi_node_mesh_parallel_I.h:680)

Indeed, when I visualize the case, four or five particles leave the domain.

Hi There,
I am an admin attempting to install liggghts on a linux compute cluster using make mpi.
I have openmpi installed and run the make mpi command whilst in the src folder.
The install seems to begin but then fails with the following error :

Hey everybody,

I'm trying to run my superquadric script parallel. But I get the error message: "ERROR on proc 3: function AtomVecSuperquadric::pack_border_hybrid is not implemented yet (../atom_vec_superquadric.cpp:720)"

Did I miss a version or is it really not implemented yet? And if it is not implemented, is there a rough idea when it will be added (if it will be added)?

Greetings,
Thomas

Hi everyone,

I was tried to install the superquadric model using the "make serial" command. The makefile has been modified to add the superquadric model. However, when compiling the executable file, it appeared the following error:

I have created a container that contains particles in Liggghts using the sph-method. This container should move in an axial direction via the “wiggle” command.

So I want to let move a surface that is defined as a wall with fix wall/region/sph with the command “wiggle”.

These two commands do not work:

fix wall all wall/region/sph myWall 0.01 2.5 wiggle amplitude 2. 0. 0. period 0.5

fix wall all wall/region/sph myWall 0.01 2.5 wiggle 2. 0. 0. 0.5 units box

Hey community,

i would like to insert 3 atom types:

1, material : cylinder surface of a rotating drum material steel

2. material : front and back covered with plexiglas / acrylic glass

3. material: particle zinc oxide

We have values for particle-steel and particle-plexiglas (Jenike Shear cell)

How do I have to set up these parameters, that I can handle these 3 different materials ? Which values are needed to be set up ?

Hello,

I'm trying to compile/install LIGGGHTS latest version but I'm having problem with the MPI.

I've set the following in [...]/LIGGGHTS-PUBLIC/src/MAKE/Makefile.user:
USE_MPI = "ON"
MPICXX_USR=/home/dventuri/intel/compilers_and_libraries_2018.2.199/linux/mpi/intel64/bin/mpicxx
MPI_INC_USR=/home/dventuri/intel/compilers_and_libraries_2018.2.199/linux/mpi/intel64/include/
MPI_LIB_USR=/home/dventuri/intel/compilers_and_libraries_2018.2.199/linux/mpi/intel64/lib/