Atom types

Submitted by jwarnett on Tue, 06/07/2011 - 12:58

Hey

easy question, I've forgotten how to do, so I thought posting on here might be quicker.

How do I define two different atom types?

Essentially I want to pour atoms in of one type, and define meshes to be the atom style of another.
With one atom type I have never had to previously define types as the following did the job]

region incyl cylinder z 0 0 0.035 0.04 0.13 units box
group nve_group region incyl
fix ins nve_group pour 25000 1 2 region incyl diam uniform 0.001 0.002 dens uniform 1500 1700

with fixes before applied to all for atom properties

Do i just need to insert
create_atoms 2 box
at the beginning? Would this create a second atom type which from now on would be reffered to as 2?

Thanks

Jay

Forums:

renekaiser | Tue, 06/07/2011 - 23:03

You have to extend the material properties, too.
As an example I pasted some parts of an input script with 3 different materials.

Rene

----------------------------------------
create_box 3 reg
...
# 1=particles 2=role 3=wall
# Material properties required for new pair styles
fix m1 all property/global youngsModulus peratomtype 2.e6 4.e6 3.e6
fix m2 all property/global poissonsRatio peratomtype 0.25 0.25 0.25
fix m3 all property/global coefficientRestitution peratomtypepair 3 &
0.70 0.55 0.50 &
0.55 0.30 0.30 &
0.50 0.30 0.30
...
#box walls
fix boxwalls_z all wall/gran/hooke/history 1 0 zplane 2.1 6.0 3
#import mesh from cad:
fix cad1 all mesh/gran printer_walze.stl 2 0.02 0.0 0.0 0.0 0. 0. 0.
fix cad2 all mesh/gran printer_kasten.stl 3 0.02 0.0 0.0 0.0 0. 0. 0.
#use the imported mesh as granular wall
fix kasten all wall/gran/hooke/history 1 0 mesh/gran 1 cad2

#particle insertion
region bc block -1.0 1.0 -1.2 1.2 2.05 6.0 units box
group nve_group region reg
fix pts1 all particletemplate/sphere 1 atom_type 1 density constant 3500 radius constant 0.015
fix pts2 all particletemplate/sphere 1 atom_type 1 density constant 2500 radius constant 0.024
fix pdd1 all particledistribution/discrete 1612 pts1 0.15 pts2 0.85
fix ins nve_group pour/dev nparticles 3000 1 distributiontemplate pdd1 &
vol 0.35 450 massflowrate 350.0 vel uniform 0. 0. 0. +0.0 -0.002 region bc