Generation of rotated regions

LAMMPS LAMMPS Mailing List Mirror
1

Hello,

My problem is related with rotate option of region command. I would appreciate if you state where I am doing something wrong.

I am trying to create 6 cylindrical regions which are connected to each other forming a polygonal ring. Orientations of the cylindrical regions are different so their longitudinal axes are not on the same plane.

For the generation of each rotated region, first I assume a region along the x axis starting at the same point and having the same length. Let’s say this vector along the x axis is A, and the vector that I want to generate is B. Then, I calculate the rotation axis as the cross product of A and B, i.e. cross(A,B), and normalize it to get a unit vector. Angle between two vectors is also calculated conventionally. So, I want to rotate the vector A to B. But, it results in cylindrical regions that are disconnected. I am using the windows version (27 Nov 2013-ICMS) of Lammps.

Attached you can see my input script for Lammps.

Thanks,

Mesut

den.in (2.12 KB)

2

Hello,

My problem is related with rotate option of region command. I would
appreciate if you state where I am doing something wrong.

nobody will debug complex input files for you. this is your job and
part of learning how to set up simulations. the best you can do is to
build your input in small steps and verify each individual step. you
can use the dump image feature in LAMMPS to immediately visualize the
result of your steps.

axel.

3

Using the rotate option with regions is for “dynamic”
rotation, meaning it occurs as a function of time during
a simulation. And they have nothing to do with creating
atoms. So I don’t see that they apply to what you
are trying to do. Maybe you want the displace_atoms
command which can rotate a group of atoms into a new
orientation in one shot, when the command is executed.

Steve