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### angle_style hybrid command

Syntax:

    angle_style hybrid style1 style2 ...

- style1,style2 = list of one or more angle styles

Examples:

    angle_style hybrid harmonic cosine
    angle_coeff 1 harmonic 80.0 1.2
    angle_coeff 2* cosine 50.0

Description:

The hybrid style enables the use of multiple angle styles in one simulation. An angle style is assigned to each angle type. For example, angles in a polymer flow (of angle type 1) could be computed with a harmonic potential and angles in the wall boundary (of angle type 2) could be computed with a cosine potential. The assignment of angle type to style is made via the angle_coeff command or in the data file.

In the angle_coeff command, the first coefficient sets the angle style and the remaining coefficients are those appropriate to that style. In the example above, the 2 angle_coeff commands would set angles of angle type 1 to be computed with a harmonic potential with coefficients 80.0, 1.2 for K, r0. All other angle types (2-N) would be computed with a cosine potential with coefficient 50.0 for K.

If the angle class2 potential is one of the hybrid styles, it requires additional BondBond and BondAngle coefficients be specified in the data file. These lines must also have an additional "class2" argument added after the angle type. For angle types which are assigned to other hybrid styles, use the style name (e.g. "harmonic") appropriate to that style. The BondBond and BondAngle coeffs for that angle type will then be ignored.

An angle style of none can be specified as the 2nd argument to the angle_coeff command, if you desire to turn off certain angle types.

Restrictions:

This angle style can only be used if LAMMPS was built with the "molecular" package (which it is by default). See the Making LAMMPS section for more info on packages.

Unlike other angle styles, the hybrid angle style does not store angle coefficient info for individual sub-styles in a binary restart files. Thus when retarting a simulation from a restart file, you need to re-specify angle_coeff commands.

Related commands:

angle_coeff

Default: none