Multi/harmonic options for bond_style and angle_style

Dear Dr. Axel Kohlmeyer and LAMMPS Users,

Hello Dr. Kohlmeyer. I see that dihedral_style multi/harmonic command allows the summation of harmonic terms. I was curious if there is the same options for bond_style and angle_style where I can obtain a bond and angle potential consisting of a sum of multiple harmonic terms.

The manual does not specify multi/harmonic options for bond_style and angle_style. I used the hybrid command but, unfortunately, it seems that I cannot use the same bond style twice. I would greatly appreciate if I could request for any advice or suggestions.

Thank you.

Sincerely,

Masato Koizumi

See the bond class2 formula. Also you could tabulate any bond
potential you like and use bond table.

Steve

See the bond class2 formula. Also you could tabulate any bond
potential you like and use bond table.
Steve

some links which might be relevant:
https://lammps.sandia.gov/doc/bond_table.html
https://lammps.sandia.gov/doc/bond_class2.html
https://lammps.sandia.gov/doc/angle_table.html
https://lammps.sandia.gov/doc/angle_class2.html
https://lammps.sandia.gov/doc/dihedral_table.html
https://lammps.sandia.gov/doc/dihedral_class2.html
https://lammps.sandia.gov/doc/dihedral_fourier.html
https://lammps.sandia.gov/doc/dihedral_spherical.html
If you receive a message ("Unknown bond style"), you might have to
compile a version of LAMMPS with the "class2" and "user-misc"
packages:
https://lammps.sandia.gov/doc/Build_package.html
https://lammps.sandia.gov/doc/Packages_details.html

unfortunately, it seems that I cannot use the same bond style twice.

LAMMPS will not complain if you define multiple bonds (and multiple
3-body angle and 4-body dihedral) interactions between the same atoms,
and you can use different parameters each time. (This is the reason I
replied to the thread.) However that's not a good idea. What Steve
suggested is much more efficient.

Andrew