Dear all,
I have the following aims:
1) to build a 100N polymer
2) to put this polymer into a sphere
point 1 is done and is functional.
Recently, I found out that a command of this type can do task 2:
fix 1 all indent 10.0 sphere v_x v_y 0.0 v_radius side in
now I have tried all possibilities and get errors such as
ERROR:variable name for fix indent does not exist
ERROR: Use of fix indent with undefined lattice
ERROR: illegal variable name for fix indent
I'd be grateful if somebody could help me to understand how to solve the problem; I apologise if this seems self-explanatory, I am a beginner.
For further details, please see files attached.
With best wishes,
Anna
bead_spring.lam.ex.100N.test (961 Bytes)
final.chain.N100.input (7.38 KB)
Dear all,
I have the following aims:
1) to build a 100N polymer
2) to put this polymer into a sphere
point 1 is done and is functional.
Recently, I found out that a command of this type can do task 2:
fix 1 all indent 10.0 sphere v_x v_y 0.0 v_radius side in
now I have tried all possibilities and get errors such as
ERROR:variable name for fix indent does not exist
ERROR: Use of fix indent with undefined lattice
ERROR: illegal variable name for fix indent
I'd be grateful if somebody could help me to understand how to solve the
problem; I apologise if this seems self-explanatory, I am a beginner.
a) you are using references to variables (v_x v_y and v_radius) but those
are not defined. you only need to use variables there, if you want to
make your indenter follow some complicated movement (i.e. change its
velocities or radius over time). you can just use a constant value there
b) add: units box
several lammps commands use by default multiples of a previously
define lattice constant to refer to coordinates. often this is kept default
for historical purposes, i.e. to not needlessly break compatibility.
cheers,
axel.