Hi all,
Greetings!
I’m running a dpd simulation with some beads carry some charges. The number of beads that carry charges is very small. say only 200 out of 200000 beads are charged. I try to use coul/cut with long cut off distance (6.0 or 8.0) instead of involving PPPM. I assume in this way it should be more efficient. Since there is only one type of beads that are charged and for this type of beads, only electrostatic interaction is needed. I prevent this type of beads from building neighbour list with other uncharged beads by using ‘neigh_modify delay 2 exclude group core notcore’ where core is the charged group. However I’m getting errors like:
ERROR on proc 6: Neighbor list overflow, boost neigh_modify one or page
I assume that this is because LAMMPS is trying to build neibouring list for all uncharged beads. Due to the long cutoff, of course the number will be huge. Of course I can boost one or page but this will be absolutely waste of time.
So is there any way I can set up exclusions in the neighbouring search for different pair interactions? say only include neighbouring search for charged groups and exclude the neighbouring search for uncharged groups for electrostatic interaction. And at mean while do normal neighbouring search for dpd interactions.
Here is part of my input file
LAMMPS Configuration file
units lj
atom_style hybrid atomic bond charge
pair_style hybrid/overlay dpd 1.0 1.0 34387 coul/cut 6.0
communicate single vel yes
bond_style harmonic
read_data DPD_2540_0.5HP50.lammps
restart 500 DPD_1.restart DPD_2.restart
#grouping
group water type 1
group decane type 2
group Ball subtract all water decane
group solvent subtract all Ball
group core type 5
group notcore subtract all core
#set charge
set group core charge 5.0
#Set rigid body for balls
fix 5 Ball rigid molecule
define masses and interaction coefficient
#Repulsion Parameters
pair_coeff 1 1 dpd 131.5 4.5 #water
pair_coeff 2 2 dpd 131.5 4.5 #Decane
pair_coeff 3 3 dpd 131.5 4.5 #AP
pair_coeff 4 4 dpd 131.5 4.5 #P
pair_coeff 5 5 dpd 131.5 4.5 #PS1
pair_coeff 1 2 dpd 198.5 4.5 #water-oil
pair_coeff 1 3 dpd 178.5 4.5 #Water-AP
pair_coeff 1 4 dpd 110 4.5 #Water-P
pair_coeff 2 3 dpd 161.5 4.5 #Deca_AP
pair_coeff 2 4 dpd 218.5 4.5 #Deca_P
pair_coeff 3 4 dpd 190 4.5 #AP-P
pair_coeff 3 5 dpd 0 4.5
pair_coeff 4 5 dpd 0 4.5
pair_coeff 1 5 dpd 0 4.5 #PS1
pair_coeff 2 5 dpd 0 4.5
bond_coeff 1 350 0.72
pair_coeff * * coul/cut
first equilibrate the initial condition
fix 1 solvent nve
create initial velocities
velocity all create 1.0 4928459 dist gaussian
change neighbor list parameters to avoid dangerous builds
neighbor 2.0 multi
neigh_modify delay 2 exclude group core notcore
Thanks a lot
Heng
2011-04-19