+Syntax: +
+angle_style cosine/delta ++
Examples: +
+angle_style cosine/delta +angle_coeff 2*4 75.0 100.0 ++
Description: +
+The cosine/delta angle style uses the potential +
+
+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 command as in the example above, or in +the data file or restart files read by the read_data +or read_restart commands: +
+Theta0 is specified in degrees, but LAMMPS converts it to radians +internally. +
+Restrictions: +
+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 for more info on packages. +
+Related commands: +
+angle_coeff, angle_style +cosine/squared +
+Default: none +
+ diff --git a/doc/angle_cosine_delta.txt b/doc/angle_cosine_delta.txt new file mode 100644 index 0000000000..afa431690d --- /dev/null +++ b/doc/angle_cosine_delta.txt @@ -0,0 +1,51 @@ +"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 cosine/delta command :h3 + +[Syntax:] + +angle_style cosine/delta :pre + +[Examples:] + +angle_style cosine/delta +angle_coeff 2*4 75.0 100.0 :pre + +[Description:] + +The {cosine/delta} angle style uses the potential + +:c,image(Eqs/angle_cosine_delta.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) +theta0 (degrees) :ul + +Theta0 is specified in degrees, but LAMMPS converts it to radians +internally. + +[Restrictions:] + +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#2_3 section for more info on packages. + +[Related commands:] + +"angle_coeff"_angle_coeff.html, "angle_style +cosine/squared"_angle_cosine_squared.html + +[Default:] none