forked from lijiext/lammps
convert math in spin and sph pair styles
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\documentclass[12pt]{article}
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\begin{document}
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$$
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p = (\gamma - 1) \rho e
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$$
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\end{document}
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\documentclass[12pt]{article}
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\begin{document}
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$$
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p = B [(\frac{\rho}{\rho_0})^{\gamma} - 1]
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$$
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\end{document}
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\documentclass[preview]{standalone}
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\usepackage{varwidth}
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\usepackage[utf8x]{inputenc}
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\usepackage{amsmath,amssymb,amsthm,bm}
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\begin{document}
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\begin{varwidth}{50in}
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\begin{equation}
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\vec{\omega}_i = -\frac{1}{\hbar} \sum_{j}^{Neighb} \vec{s}_{j}\times \left(\vec{e}_{ij}\times \vec{D} \right)
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~~{\rm and}~~
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\vec{F}_i = -\sum_{j}^{Neighb} \frac{1}{r_{ij}} \vec{D} \times \left( \vec{s}_{i}\times \vec{s}_{j} \right)
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, \nonumber
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\end{equation}
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\end{varwidth}
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\end{document}
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\documentclass[preview]{standalone}
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\usepackage{varwidth}
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\usepackage[utf8x]{inputenc}
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\usepackage{amsmath,amssymb,amsthm,bm}
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\begin{document}
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\begin{varwidth}{50in}
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\begin{equation}
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\bm{H}_{dm} = \sum_{{ i,j}=1,i\neq j}^{N}
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\left( \vec{e}_{ij} \times \vec{D} \right)
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\cdot\left(\vec{s}_{i}\times \vec{s}_{j}\right),
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\nonumber
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\end{equation}
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\end{varwidth}
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\end{document}
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\vec{D}\left(r_{ij}\right)
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{\rm ~and~} \vec{D}\left(r_{ij}\right) = \vec{e}_{ij} \times \vec{D}
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@ -47,11 +47,13 @@ imagine for a mesoscopic particle.
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The pressure forces between particles will be computed according to
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Tait's equation of state:
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.. image:: Eqs/pair_sph_tait.jpg
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:align: center
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.. math::
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where gamma = 7 and B = c\_0\^2 rho\_0 / gamma, with rho\_0 being the
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reference density and c\_0 the reference speed of sound.
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p = B [(\frac{\rho}{\rho_0})^{\gamma} - 1]
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where :math:`\gamma = 7` and :math:`B = c_0^2 \rho_0 / \gamma`, with
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:math:`\rho_0` being the reference density and :math:`c_0` the reference
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speed of sound.
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The laminar viscosity and the random forces will be computed according
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to formulas described in :ref:`(Espanol and Revenga) <Espanol_Revenga>`.
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@ -75,11 +77,10 @@ The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above.
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* rho0 reference density (mass/volume units)
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* c0 reference soundspeed (distance/time units)
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* :math:`\rho_0` reference density (mass/volume units)
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* :math:`c_0` reference soundspeed (distance/time units)
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* h kernel function cutoff (distance units)
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----------
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@ -107,7 +108,8 @@ if LAMMPS was built with that package. See the :doc:`Build package <Build_packa
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Related commands
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""""""""""""""""
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:doc:`pair coeff <pair_coeff>`, :doc:`pair sph/rhosum <pair_sph_rhosum>`
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:doc:`pair coeff <pair_coeff>`, :doc:`pair sph/rhosum <pair_sph_rhosum>`,
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:doc:`pair sph/taitwater <pair_sph_taitwater>`
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Default
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"""""""
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@ -26,13 +26,15 @@ Description
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The sph/idealgas style computes pressure forces between particles
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according to the ideal gas equation of state:
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.. image:: Eqs/pair_sph_ideal.jpg
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:align: center
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.. math::
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where gamma = 1.4 is the heat capacity ratio, rho is the local
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density, and e is the internal energy per unit mass. This pair style
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also computes Monaghan's artificial viscosity to prevent particles
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from interpenetrating :ref:`(Monaghan) <ideal-Monoghan>`.
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p = (\gamma - 1) \rho e
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where :math:`\gamma = 1.4` is the heat capacity ratio, :math:`\rho` is
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the local density, and e is the internal energy per unit mass. This
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pair style also computes Monaghan's artificial viscosity to prevent
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particles from interpenetrating :ref:`(Monaghan) <ideal-Monoghan>`.
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See `this PDF guide <USER/sph/SPH_LAMMPS_userguide.pdf>`_ to using SPH in
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LAMMPS.
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@ -41,7 +43,7 @@ The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above.
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* nu artificial viscosity (no units)
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* :math:`\nu` artificial viscosity (no units)
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* h kernel function cutoff (distance units)
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@ -37,7 +37,7 @@ The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above.
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* nu artificial viscosity (no units)
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* :math:`\nu` artificial viscosity (no units)
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* h kernel function cutoff (distance units)
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@ -26,11 +26,14 @@ Description
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The sph/taitwater style computes pressure forces between SPH particles
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according to Tait's equation of state:
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.. image:: Eqs/pair_sph_tait.jpg
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:align: center
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.. math::
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where gamma = 7 and B = c\_0\^2 rho\_0 / gamma, with rho\_0 being the
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reference density and c\_0 the reference speed of sound.
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p = B \biggl[\left(\frac{\rho}{\rho_0}\right)^{\gamma} - 1\biggr]
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where :math:`\gamma = 7` and :math:`B = c_0^2 \rho_0 / \gamma`, with
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:math:`\rho_0` being the reference density and :math:`c_0` the reference
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speed of sound.
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This pair style also computes Monaghan's artificial viscosity to
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prevent particles from interpenetrating :ref:`(Monaghan) <Monaghan>`.
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@ -42,9 +45,9 @@ The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above.
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* rho0 reference density (mass/volume units)
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* c0 reference soundspeed (distance/time units)
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* nu artificial viscosity (no units)
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* :math:`\rho_0` reference density (mass/volume units)
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* :math:`c_0` reference soundspeed (distance/time units)
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* :math:`\nu` artificial viscosity (no units)
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* h kernel function cutoff (distance units)
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@ -26,11 +26,14 @@ Description
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The sph/taitwater/morris style computes pressure forces between SPH
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particles according to Tait's equation of state:
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.. image:: Eqs/pair_sph_tait.jpg
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:align: center
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.. math::
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where gamma = 7 and B = c\_0\^2 rho\_0 / gamma, with rho\_0 being the
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reference density and c\_0 the reference speed of sound.
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p = B \biggl[\left(\frac{\rho}{\rho_0}\right)^{\gamma} - 1\biggr]
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where :math:`\gamma = 7` and :math:`B = c_0^2 \rho_0 / \gamma`, with
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:math:`\rho_0` being the reference density and :math:`c_0` the reference
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speed of sound.
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This pair style also computes laminar viscosity :ref:`(Morris) <Morris>`.
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@ -41,9 +44,9 @@ The following coefficients must be defined for each pair of atoms
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types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
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above.
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* rho0 reference density (mass/volume units)
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* c0 reference soundspeed (distance/time units)
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* nu dynamic viscosity (mass\*distance/time units)
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* :math:`\rho_0` reference density (mass/volume units)
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* :math:`c_0` reference soundspeed (distance/time units)
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* :math:`\nu` dynamic viscosity (mass\*distance/time units)
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* h kernel function cutoff (distance units)
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@ -43,12 +43,38 @@ The magnetic dipole-dipole interactions are computed by the
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following formulas for the magnetic energy, magnetic precession
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vector omega and mechanical force between particles I and J.
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.. image:: Eqs/pair_spin_dipole.jpg
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:align: center
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.. math::
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where si and sj are the spin on two magnetic particles,
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r is their separation distance, and the vector e = (Ri - Rj)/\|Ri - Rj\|
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is the direction vector between the two particles.
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\mathcal{H}_{\rm long} & =
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-\frac{\mu_{0} \left( \mu_B\right)^2}{4\pi}
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\sum_{i,j,i\neq j}^{N}
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\frac{g_i g_j}{r_{ij}^3}
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\biggl(3
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\left(\vec{e}_{ij}\cdot \vec{s}_{i}\right)
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\left(\vec{e}_{ij}\cdot \vec{s}_{j}\right)
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-\vec{s}_i\cdot\vec{s}_j \biggr) \\
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\mathbf{\omega}_i & =
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\frac{\mu_0 (\mu_B)^2}{4\pi\hbar}\sum_{j}
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\frac{g_i g_j}{r_{ij}^3}
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\, \biggl(
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3\,(\vec{e}_{ij}\cdot\vec{s}_{j})\vec{e}_{ij}
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-\vec{s}_{j} \biggr) \\
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\mathbf{F}_i & =
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\frac{3\, \mu_0 (\mu_B)^2}{4\pi} \sum_j
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\frac{g_i g_j}{r_{ij}^4}
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\biggl[\bigl( (\vec{s}_i\cdot\vec{s}_j)
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-5(\vec{e}_{ij}\cdot\vec{s}_i)
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(\vec{e}_{ij}\cdot\vec{s}_j)\bigr) \vec{e}_{ij}+
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\bigl(
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(\vec{e}_{ij}\cdot\vec{s}_i)\vec{s}_j+
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(\vec{e}_{ij}\cdot\vec{s}_j)\vec{s}_i
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\bigr)
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\biggr]
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where :math:`\vec{s}_i` and :math:`\vec{s}_j` are the spin on two magnetic
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particles, r is their separation distance, and the vector :math:`\vec{e}_{ij}
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= \frac{r_i - r_j}{\left| r_i - r_j \right|}` is the direction vector
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between the two particles.
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Style *spin/dipole/long* computes long-range magnetic dipole-dipole
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interaction.
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@ -32,15 +32,19 @@ between pairs of magnetic spins.
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According to the expression reported in :ref:`(Rohart) <Rohart>`, one has
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the following DM energy:
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.. image:: Eqs/pair_spin_dmi_interaction.jpg
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:align: center
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.. math::
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where si and sj are two neighboring magnetic spins of two particles,
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eij = (ri - rj)/\|ri-rj\| is the unit vector between sites i and j,
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and D is the DM vector defining the intensity (in eV) and the direction
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of the interaction.
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\mathbf{H}_{dm} = \sum_{{ i,j}=1,i\neq j}^{N}
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\left( \vec{e}_{ij} \times \vec{D} \right)
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\cdot\left(\vec{s}_{i}\times \vec{s}_{j}\right),
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In :ref:`(Rohart) <Rohart>`, D is defined as the direction normal to the film oriented
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where :math:`\vec{s}_i` and :math:`\vec{s}_j` are two neighboring magnetic spins of
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two particles, :math:`\vec{e}_ij = \frac{r_i - r_j}{\left| r_i - r_j \right|}`
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is the unit vector between sites *i* and *j*, and :math:`\vec{D}` is the
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DM vector defining the intensity (in eV) and the direction of the
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interaction.
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In :ref:`(Rohart) <Rohart>`, :math:`\vec{D}` is defined as the direction normal to the film oriented
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from the high spin-orbit layer to the magnetic ultra-thin film.
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The application of a spin-lattice Poisson bracket to this energy (as described
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@ -48,8 +52,11 @@ in :ref:`(Tranchida) <Tranchida5>`) allows to derive a magnetic torque omega, an
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mechanical force F (for spin-lattice calculations only) for each magnetic
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particle i:
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.. image:: Eqs/pair_spin_dmi_forces.jpg
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:align: center
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.. math::
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\vec{\omega}_i = -\frac{1}{\hbar} \sum_{j}^{Neighb} \vec{s}_{j}\times \left(\vec{e}_{ij}\times \vec{D} \right)
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~~{\rm and}~~
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\vec{F}_i = -\sum_{j}^{Neighb} \frac{1}{r_{ij}} \vec{D} \times \left( \vec{s}_{i}\times \vec{s}_{j} \right)
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More details about the derivation of these torques/forces are reported in
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:ref:`(Tranchida) <Tranchida5>`.
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@ -93,11 +100,8 @@ Related commands
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----------
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.. _Rohart:
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.. _Tranchida5:
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**(Rohart)** Rohart and Thiaville,
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@ -30,24 +30,29 @@ Style *spin/me* computes a magneto-electric interaction between
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pairs of magnetic spins. According to the derivation reported in
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:ref:`(Katsura) <Katsura1>`, this interaction is defined as:
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.. image:: Eqs/pair_spin_me_interaction.jpg
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:align: center
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.. math::
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where si and sj are neighboring magnetic spins of two particles,
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eij = (ri - rj)/\|ri-rj\| is the normalized separation vector between the
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two particles, and E is an electric polarization vector.
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The norm and direction of E are giving the intensity and the
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direction of a screened dielectric atomic polarization (in eV).
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\vec{\omega}_i & = -\frac{1}{\hbar} \sum_{j}^{Neighb} \vec{s}_{j}\times\vec{D}(r_{ij}) \\
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\vec{F}_i & = -\sum_{j}^{Neighb} \frac{\partial D(r_{ij})}{\partial r_{ij}} \left(\vec{s}_{i}\times \vec{s}_{j} \right) \cdot \vec{r}_{ij}
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where :math:`\vec{s}_i` and :math:`\vec{s}_j` are neighboring magnetic
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spins of two particles.
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From this magneto-electric interaction, each spin i will be submitted
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to a magnetic torque omega, and its associated atom can be submitted to a
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force F for spin-lattice calculations (see :doc:`fix nve/spin <fix_nve_spin>`),
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such as:
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.. image:: Eqs/pair_spin_me_forces.jpg
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:align: center
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.. math::
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\vec{F}^{i} & = -\sum_{j}^{Neighbor} \left( \vec{s}_{i}\times \vec{s}_{j} \right) \times \vec{E} \\
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\vec{\omega}^{i} = -\frac{1}{\hbar} \sum_{j}^{Neighbor} \vec{s}_j \times \left(\vec{E}\times r_{ij} \right)
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with h the Planck constant (in metal units) and :math:`\vec{E}` an
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electric polarization vector. The norm and direction of E are giving
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the intensity and the direction of a screened dielectric atomic
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polarization (in eV).
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with h the Planck constant (in metal units).
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More details about the derivation of these torques/forces are reported in
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:ref:`(Tranchida) <Tranchida4>`.
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