[lammps-users] question about hybrid angle style for class2 and harmonic


I tried to use hybrid angle style
angle_style hybrid class2 harmonic
angle_coeff 1 class2 109.49 38.88670372 -0.544413852 0.002177655
angle_coeff 2 harmonic 200 104.52

but got the following error
Invalid coeffs for this angle style
Cannot set class 2 coeffs in data file for this angle style.

based on manual,
BondBond and BondAngle Coeffs have to be set in data file. If I don’t set these two parameters in data file, then I got the error of missing coeffs

I am afraid this is bug. If anyone knows how to get around it. Could you give me a hint for it?


You can do it, but you need to also add the keyword harmonic or class2
to the BondBond and BondAngle settings in the data file. See the
attached 2 files for a simple example. Note that since BondBond is
only defined for class2 and not harmonic, you need to set all of them
to class2, even those that are not defined b/c those angle types are
harmonic (just use 0.0 as placeholders).


in.class2.hybrid (460 Bytes)

data.class2.hybrid (25.4 KB)