"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)

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angle_style mm3 command :h3

[Syntax:]

angle_style mm3 :pre

[Examples:]

angle_style mm3
angle_coeff 1 100.0 107.0 :pre

[Description:]

The {mm3} angle style uses the potential that is anharmonic in the angle
as defined in "(Allinger)"_#mm3-allinger1989

:c,image(Eqs/angle_mm3.jpg)

where theta0 is the equilibrium value of the angle, and K is a
prefactor. The anharmonic prefactors have units deg^(-n), for example
-0.014 deg^(-1), 5.6(10)^(-5) deg^(-2), ...

The following coefficients must be defined for each angle type via the
"angle_coeff"_angle_coeff.html command as in the example above, or in
the data file or restart files read by the "read_data"_read_data.html
or "read_restart"_read_restart.html commands:

K (energy/radian^2)
theta0 (degrees) :ul

Theta0 is specified in degrees, but LAMMPS converts it to radians
internally; hence the units of K are in energy/radian^2.

[Restrictions:]

This angle style can only be used if LAMMPS was built with the
USER_YAFF package.  See the "Build package"_Build_package.html doc
page for more info.

[Related commands:]

"angle_coeff"_angle_coeff.html

[Default:] none

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