Hi Lammps Users

I am trying to run a polymer chain simulation. I defined the bond and angle as per the "table" style requirement.

bond_style table spline 10000

bond_coeff 1 Coeff_Bond_Table bond_type_1

bond_coeff 2 Coeff_Bond_Table bond_type_2

bond_coeff 3 Coeff_Bond_Table bond_type_3

angle_style table spline 1500

angle_coeff 1 Coeff_Angle_Table angle_type_1

angle_coeff 2 Coeff_Angle_Table angle_type_2

angle_coeff 3 Coeff_Angle_Table angle_type_3

angle_coeff 4 Coeff_Angle_Table angle_type_4

angle_coeff 5 Coeff_Angle_Table angle_type_5

angle_coeff 6 Coeff_Angle_Table angle_type_6

I initially had only the distance/angle and energy values for all bond and angle types.

I used the following lines in python to create force and derivative values:

cs = CubicSpline(bondlengthList, energyList)

forceList = cs(bondlengthList, 1)

cs = CubicSpline(angleList, energyList)

energyDerivativeList = cs(angleList, 1)

Is this a correct method? After using these force values in the bond and angle table, I get the following warning messages and a segmentation fault. Could someone help me to understand and rectify it.

WARNING: 1490 of 1501 force values in table are inconsistent with -dE/dr. Should only be flagged at inflection points

WARNING: 1490 of 1501 force values in table are inconsistent with -dE/dr. Should only be flagged at inflection points

WARNING: 1492 of 1501 force values in table are inconsistent with -dE/dr. Should only be flagged at inflection points