fene bond too long

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1

Hi,
I have a fene potential like this :

bond_style fene
bond_coeff 1 30 1.2 1.0 1.0

but I always get this errors :

Special bond factors coul: 0 0 0
3 = max # of 1-2 neighbors
3 = max # of 1-3 neighbors
6 = max # of 1-4 neighbors
9 = max # of special neighbors
WARNING: Resetting reneighboring criteria during minimization (…/min.cpp:168)
WARNING: Use special bonds = 0,1,1 with bond style fene (…/bond_fene.cpp:188)
Neighbor list info …
1 neighbor list requests
update every 1 steps, delay 0 steps, check yes
max neighbors/atom: 2000, page size: 100000
master list distance cutoff = 3.12
ghost atom cutoff = 3.12
binsize = 1.56, bins = 135 129 129
Setting up cg style minimization …
Unit style : lj
WARNING: FENE bond too long: 0 47 48 20.5183 (…/bond_fene.cpp:91)
ERROR on proc 0: Bad FENE bond (…/bond_fene.cpp:92)

I have checked my polymer bonds and I’m quite sure that they are shorter than 2.
how can I fix this?Is there something wrong with my neighbour command?

neighbor .3 bin

thanks

2

Hi,
I have a fene potential like this :
bond_style fene
bond_coeff 1 30 1.2 1.0 1.0
but I always get this errors :

Special bond factors coul: 0 0 0
  3 = max # of 1-2 neighbors
  3 = max # of 1-3 neighbors
  6 = max # of 1-4 neighbors
  9 = max # of special neighbors
WARNING: Resetting reneighboring criteria during minimization
(../min.cpp:168)
WARNING: Use special bonds = 0,1,1 with bond style fene
(../bond_fene.cpp:188)
Neighbor list info ...
  1 neighbor list requests
  update every 1 steps, delay 0 steps, check yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 3.12
  ghost atom cutoff = 3.12
  binsize = 1.56, bins = 135 129 129
Setting up cg style minimization ...
  Unit style : lj
WARNING: FENE bond too long: 0 47 48 20.5183 (../bond_fene.cpp:91)
ERROR on proc 0: Bad FENE bond (../bond_fene.cpp:92)

I have checked my polymer bonds and I'm quite sure that they are shorter
than 2.

well, the warning message tells you exactly which bond to look at.

how can I fix this?

correct your geometry or your bond topology.

Is there something wrong with my neighbour command?
neighbor .3 bin

no. but there is a warning about special_bonds that should be
addressed, if you want to have a correct simulation after you have
corrected for the issue with the incorrect bond.

axel.