# angle_style hybrid command

## Syntax

``` LAMMPS
angle_style hybrid style1 style2 ...
```

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

## Examples

``` LAMMPS
angle_style hybrid harmonic cosine
angle_coeff 1 harmonic 80.0 30.0
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](angle_coeff) command or in
the data file.

In the [angle_coeff](angle_coeff) commands, the name of an angle style
must be added after the angle type, with the remaining coefficients
being those appropriate to that style. In the example above, the 2
angle_coeff commands set angles of angle type 1 to be computed with a
*harmonic* potential with coefficients 80.0, 30.0 for $K$, $\theta_0$.
All other angle types $(2 - N)$ are computed with a *cosine* potential
with coefficient 50.0 for $K$.

If angle coefficients are specified in the data file read via the
[read_data](read_data) command, then the same rule applies. E.g.
\"harmonic\" or \"cosine\", must be added after the angle type, for each
line in the \"Angle Coeffs\" section, e.g.

    Angle Coeffs

    1 harmonic 80.0 30.0
    2 cosine 50.0
    ...

If *class2* is one of the angle hybrid styles, the same rule holds for
specifying additional BondBond (and BondAngle) coefficients either via
the input script or in the data file. I.e. *class2* must be added to
each line after the angle type. For lines in the BondBond (or BondAngle)
section of the data file for angle types that are not *class2*, you must
use an angle style of *skip* as a placeholder, e.g.

    BondBond Coeffs

    1 skip
    2 class2 3.6512 1.0119 1.0119
    ...

Note that it is not necessary to use the angle style *skip* in the input
script, since BondBond (or BondAngle) coefficients need not be specified
at all for angle types that are not *class2*.

An angle style of *none* with no additional coefficients can be used in
place of an angle style, either in a input script
[angle_coeff](angle_coeff) command or in the data file, if you desire to
turn off interactions for specific angle types.

------------------------------------------------------------------------

## Restrictions

This angle style can only be used if LAMMPS was built with the MOLECULE
package. See the [Build package](Build_package) doc page for more info.

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

## Related commands

[angle_coeff](angle_coeff)

## Default

none