LIGGGHTS® - Developer Forum

There is an error in create_atoms.cpp::Line 130
It uses arg[2] as the random number seed instead of arg[3]

Since the release of LIGGGHTS 3.5.0 seeds for particle insertion need to be prime numbers when I am informend correctly. However, when I consider the Park-Miller pseudorandom number generator as generator for "random" particle positions and velocities I do not get the point why the seeding should be larger than 10 000 and a prime number. As far as I know this random number generator creates a periodic list of numbers, where all numbers in a range from 1 to 2^31-1 do exist. Different seeds only shift the starting point, not the numbers itself.

Hi,

I am trying to implement a non-contact force with walls in LIGGGHTS (e.g. lubrication force). I have noticed that in fix_wall_gran.cpp, deltan is used to calculate the overlap with wall and restricted to < 0. My plan is to use the deltan as the separation distance when it is > 0. The following are the relative codes in fix_wall_gran.cpp (from line 987 to 1009, I add my lines after that.) Is it feasible to do so?

if(deltan <= 0 || (radius && deltan < contactDistanceMultiplier*radius[iPart]))
{

Hello everybody, lately I've been reading LIGGGHTS-PUBLIC version 3.5.0 code to have a better understanding about atoms migration scheme. I found that two methods are available, Comm::exchange() and Irregular::migrate_atoms().

I decided to give a chance to Irreglar::migrate_atoms() and made a couple of changes in verlet.cpp file in order to use this method. The changes are very few, so I guess they are alright; here they are:

1) around line 73 added an include sentence:

#include "irregular.h" (this way Verlet class are aware of Irregular class and methods)

Hello,
I'm posting what I have done to incorporate damping into a flexible fiber model.
I am using Yu Guo's paper "Granular Shear Flows of Flexible Rod-like Particles"
https://www.researchgate.net/publication/258741920_Granular_Shear_Flows_...
This release currently works for LIGGGHTS 3.7.0
The only thing that i would like to explore further is this bond model interaction with the fix_template_multiplespheres command.

Hello all,

Is it possible to access contact information (contact point, overlap) in fix_ave_euler.cpp?
Any idea how this can be done?

Thanks and kind regards,
Vinay

Hi all,

I am working in a code to coupling code_aster (http://www.code-aster.org/) and LIGGGHTS.
Do to this, I compiled LIGGGHTS with the libraries that make possible LIGGGHTS work with meshes in med (Modélisation et Echange de Données - http://www.code-aster.org/spip.php?article275) format.
I share all the work here in hope that can be useful to someone.

hello,

I am using dump local/gran/vtk command as follow to visualize forcechain in paraview:

dump forcechain all local/gran/vtk 1000 dump*.vtk

However, I get the following error:

ERROR: dump local/gran/vtk requires 6 arguments (../dump_local_gran_vtk.cpp:94)

Unfortunately, I cannot find any information about this dump style in online documentation of LIGGGHTS 3.X (The online manual). I would appreciate if anyone could tell me what arguments are needed for this dump style.

Thank you,
Nina

Hello,
I have been trying to modify the verlet files to create a runge_kutta integration class for academic reasons...
I have added the variable bool has_converged as a protected variable, and a public function virtual void set_has_converged as follows

#ifdef INTEGRATE_CLASS

IntegrateStyle(my_rk,my_rk)

#else

#ifndef LMP_MY_RK_H
#define LMP_MY_RK_H

#include "integrate.h"

namespace LAMMPS_NS {

I successfully compiled the serial executable on my windows machine via cygwin but when i tried to run a script it showing following error.

$ lmp_serial