lammps/doc/src/min_spin.txt

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"LAMMPS WWW Page"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Commands_all.html)
:line
min_style spin command :h3
[Syntax:]
min_style spin :pre
[Examples:]
min_style spin :pre
[Description:]
Apply a minimization algorithm to use when a "minimize"_minimize.html
command is performed.
Style {spin} defines a damped spin dynamics with an adaptive
timestep, according to:
:c,image(Eqs/min_spin_damping.jpg)
with lambda a damping coefficient (similar to a Gilbert
damping).
Lambda can be defined by setting the {alpha_damp} keyword with the
"min_modify"_min_modify.html command.
The minimization procedure solves this equation using an
adaptive timestep. The value of this timestep is defined
by the largest precession frequency that has to be solved in the
system:
:c,image(Eqs/min_spin_timestep.jpg)
with {|omega|_{max}} the norm of the largest precession frequency
in the system (across all processes, and across all replicas if a
spin/neb calculation is performed).
Kappa defines a discretization factor {discrete_factor} for the
definition of this timestep.
{discrete_factor} can be defined with the "min_modify"_min_modify.html
command.
NOTE: The {spin} style replaces the force tolerance by a torque
tolerance. See "minimize"_minimize.html for more explanation.
[Restrictions:]
This minimization procedure is only applied to spin degrees of
freedom for a frozen lattice configuration.
[Related commands:]
"min_style"_min_style.html, "minimize"_minimize.html,
"min_modify"_min_modify.html
[Default:]
The option defaults are {alpha_damp} = 1.0 and {discrete_factor} =
10.0.