"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

improper_style fourier command :h3

[Syntax:]

improper_style fourier :pre

[Examples:]

improper_style fourier
improper_coeff 1 100.0 180.0 :pre

[Description:]

The {fourier} improper style uses the following potential:

:c,image(Eqs/improper_fourier.jpg)

where K is the force constant and omega is the angle between the IL
axis and the IJK plane:

:c,image(Eqs/umbrella.jpg)

If all parameter (see bellow) is not zero, the all the three possible angles will taken in account.

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)
C0 (real)
C1 (real)
C2 (real)
all  (integer >= 0) :ul

:line

[Restrictions:]

This angle style can only be used if LAMMPS was built with the
USER_MISC package.  See the "Making LAMMPS"_Section_start.html#start_3 
section for more info on packages.

[Related commands:]

"improper_coeff"_improper_coeff.html

[Default:] none

:line

:link(Mayo)
[(Mayo)] Mayo, Olfason, Goddard III, J Phys Chem, 94, 8897-8909
(1990),
