Hi all.
I am attempting to simulate some fene chains in LJ units using a Debye Huckel Potential. For sigma=1nm and epsilon=1kBT, I have used the standard bond_coeff values as:
bond_coeff 1 30.0 1.5 1.0 0.5.
Now, I am simulating a new system in which the size of my polymer chain is 0.5nm, thus sigma=0.5nm and epsilon=1kBT. Am I correct to interpret that for my reference distance (sigma=0.5nm) my bond coefficient values should become:
bond_coeff 1 120 0.75 1.0 0.5
Similarly, if my debye length is 1nm, would by kappa (for sigma=0.5nm) become:
kappa=1/(1nm/0.5nm)=2
Lastly, I define my pair_coeff for WCA + DH as:
pair_coeff 1 1 1.0 0.5 0.561 4.0
I want to confirm I am understanding the use of my reference distance value correctly since my simulation gives me a “Bad FENE bond” error after several “FENE bond too long” warnings.
I simulate in the nvt ensemble using: fix 3 all nvt temp 1.0 1.0 100.0 #NVT
Thanks in advance for the help.