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

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

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improper_style harmonic command :h3

[Syntax:]

improper_style harmonic :pre

[Examples:]

improper_style harmonic
improper_coeff 1 100.0 0 :pre

[Description:]

The {harmonic} improper style uses the potential

:c,image(Eqs/improper_harmonic.jpg)

where X is the improper angle, X0 is its equilibrium value, and K is a
prefactor.  Note that the usual 1/2 factor is included in K.

The following coefficients must be defined for each improper type via the
"improper_coeff"_improper_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)
X0 (degrees) :ul

X0 is specified in degrees, but LAMMPS converts it to radians
internally; hence the units of K are in energy/radian^2.

[Restrictions:] none

[Related commands:]

"improper_coeff"_improper_coeff.html

[Default:] none