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Correcting some aspects of the SPIN package documentation.

This commit is contained in:
Julien Tranchida 2022-09-26 07:43:19 +02:00
parent 1ef2c8c5dc
commit 90f26f05fc
4 changed files with 17 additions and 13 deletions
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16
doc/src/Howto_spins.rst
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@ -30,9 +30,11 @@ can be coupled to another Langevin thermostat applied to the atoms
using :doc:`fix langevin <fix_langevin>` in order to simulate using :doc:`fix langevin <fix_langevin>` in order to simulate
thermostatted spin-lattice systems. thermostatted spin-lattice systems.
The magnetic Gilbert damping can also be applied using :doc:`fix langevin/spin <fix_langevin_spin>`. It allows to either dissipate The magnetic damping can also be applied
the thermal energy of the Langevin thermostat, or to perform a using :doc:`fix langevin/spin <fix_langevin_spin>`.
relaxation of the magnetic configuration toward an equilibrium state. It allows to either dissipate the thermal energy of the Langevin
thermostat, or to perform a relaxation of the magnetic configuration
toward an equilibrium state.
The command :doc:`fix setforce/spin <fix_setforce>` allows to set the The command :doc:`fix setforce/spin <fix_setforce>` allows to set the
components of the magnetic precession vectors (while erasing and components of the magnetic precession vectors (while erasing and
@ -52,9 +54,11 @@ All the computed magnetic properties can be output by two main
commands. The first one is :doc:`compute spin <compute_spin>`, that commands. The first one is :doc:`compute spin <compute_spin>`, that
enables to evaluate magnetic averaged quantities, such as the total enables to evaluate magnetic averaged quantities, such as the total
magnetization of the system along x, y, or z, the spin temperature, or magnetization of the system along x, y, or z, the spin temperature, or
the magnetic energy. The second command is :doc:`compute property/atom <compute_property_atom>`. It enables to output all the the magnetic energy. The second command
per atom magnetic quantities. Typically, the orientation of a given is :doc:`compute property/atom <compute_property_atom>`.
magnetic spin, or the magnetic force acting on this spin. It enables to output all the per atom magnetic quantities. Typically,
the orientation of a given magnetic spin, or the magnetic force
acting on this spin.
---------- ----------

4
doc/src/fix_langevin_spin.rst
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@ -40,7 +40,7 @@ the following stochastic differential equation:
\times\left( \vec{\omega}_{i} \times\vec{s}_{i} \right) \right) \times\left( \vec{\omega}_{i} \times\vec{s}_{i} \right) \right)
with :math:`\lambda` the transverse damping, and :math:`\eta` a random vector. with :math:`\lambda` the transverse damping, and :math:`\eta` a random vector.
This equation is referred to as the stochastic Landau-Lifshitz-Gilbert (sLLG) This equation is referred to as the stochastic Landau-Lifshitz (sLL)
equation. equation.
The components of :math:`\eta` are drawn from a Gaussian probability The components of :math:`\eta` are drawn from a Gaussian probability
@ -49,7 +49,7 @@ the external thermostat T (in K in metal units).
More details about this implementation are reported in :ref:`(Tranchida) <Tranchida2>`. More details about this implementation are reported in :ref:`(Tranchida) <Tranchida2>`.
Note: due to the form of the sLLG equation, this fix has to be defined just Note: due to the form of the sLL equation, this fix has to be defined just
before the nve/spin fix (and after all other magnetic fixes). before the nve/spin fix (and after all other magnetic fixes).
As an example: As an example:

8
doc/src/min_modify.rst
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@ -24,7 +24,7 @@ Syntax
inf = max force component across all 3-vectors inf = max force component across all 3-vectors
max = max force norm across all 3-vectors max = max force norm across all 3-vectors
*alpha_damp* value = damping *alpha_damp* value = damping
damping = fictitious Gilbert damping for spin minimization (adim) damping = fictitious magnetic damping for spin minimization (adim)
*discrete_factor* value = factor *discrete_factor* value = factor
factor = discretization factor for adaptive spin timestep (adim) factor = discretization factor for adaptive spin timestep (adim)
*integrator* value = *eulerimplicit* or *verlet* *integrator* value = *eulerimplicit* or *verlet*
@ -109,9 +109,9 @@ norm is replaced by the spin-torque norm.
Keywords *alpha_damp* and *discrete_factor* only make sense when Keywords *alpha_damp* and *discrete_factor* only make sense when
a :doc:`min_spin <min_spin>` command is declared. a :doc:`min_spin <min_spin>` command is declared.
Keyword *alpha_damp* defines an analog of a magnetic Gilbert Keyword *alpha_damp* defines an analog of a magnetic damping.
damping. It defines a relaxation rate toward an equilibrium for It defines a relaxation rate toward an equilibrium for a given
a given magnetic system. magnetic system.
Keyword *discrete_factor* defines a discretization factor for the Keyword *discrete_factor* defines a discretization factor for the
adaptive timestep used in the *spin* minimization. adaptive timestep used in the *spin* minimization.
See :doc:`min_spin <min_spin>` for more information about those See :doc:`min_spin <min_spin>` for more information about those

2
doc/src/min_spin.rst
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@ -39,7 +39,7 @@ timestep, according to:
\frac{d \vec{s}_{i}}{dt} = \lambda\, \vec{s}_{i} \times\left( \vec{\omega}_{i} \times\vec{s}_{i} \right) \frac{d \vec{s}_{i}}{dt} = \lambda\, \vec{s}_{i} \times\left( \vec{\omega}_{i} \times\vec{s}_{i} \right)
with :math:`\lambda` a damping coefficient (similar to a Gilbert with :math:`\lambda` a damping coefficient (similar to a magnetic
damping). :math:`\lambda` can be defined by setting the damping). :math:`\lambda` can be defined by setting the
*alpha_damp* keyword with the :doc:`min_modify <min_modify>` command. *alpha_damp* keyword with the :doc:`min_modify <min_modify>` command.