lammps/doc/angle_harmonic.txt

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"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)
:line
angle_style harmonic command :h3
[Syntax:]
angle_style harmonic :pre
[Examples:]
angle_style harmonic
angle_coeff 1 300.0 107.0 :pre
[Description:]
The {harmonic} angle style uses the potential
:c,image(Eqs/angle_harmonic.jpg)
where theta0 is the equilibrium value of the angle, and K is a
prefactor. Note that the usual 1/2 factor is included in K.
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:] none
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_start.html#start_3 section for more info on packages.
[Related commands:]
"angle_coeff"_angle_coeff.html
[Default:] none