min_style spin command

Syntax

min_style spin

Examples

min_style    spin

Description

Apply a minimization algorithm to use when a minimize command is performed.

Style spin defines a damped spin dynamics with an adaptive timestep, according to:

_images/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 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:

_images/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 command.

Note

The spin style replaces the force tolerance by a torque tolerance. See minimize for more explanation.

Restrictions

This minimization procedure is only applied to spin degrees of freedom for a frozen lattice configuration.

Default

The option defaults are alpha_damp = 1.0 and discrete_factor = 10.0.