Dear Lammps Users,
I am trying to compress a fluid between surfaces and then I’d like to apply a shear. I process as follows:
I create two input files, one for compression and one for shearing.
I define a group of atoms with the group command in the first input and wrote their index in a file using group2ndx.
In the second input file I would like to read the previously generated file.ndx using the ndx2group command.
My understanding is that this will allow me to define the group in the first input (compression stage) but use it also in the second input (shearing stage) without having to define it explicitly again.
The problem is that the ndx2group processes the file but no group is created and the simulations crash
To test the command I decided to run a simpler simulation, I modified the in.flow.couette input file from the examples (examples/flow) to first generate the ndx file and then read it in the next run. It still crashes saying that no group has been found
LAMMPS VERSION: 8 February 2023 with COLVARS package installed.
Attached is the relevant file input file
in.flow.couette (1.5 KB)
I hope that my explanation was clear.