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

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1

Hello:

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?

Thanks,
Hai

2

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).

Steve

in.class2.hybrid (460 Bytes)

data.class2.hybrid (25.4 KB)