Update docs: bond_harmonic_shift

\documentclass[12pt]{article}

\begin{document}

$$

   E = \frac{Umin}{(r_0-r_c)^2} \left[ (r-r_0)^2-(r_c-r_0)^2 \right] 

$$

\end{document}

 No newline at end of file

.. index:: bond\_style harmonic/shift

.. index:: bond_style harmonic/shift

bond\_style harmonic/shift command

==================================

bond_style harmonic/shift command

=================================

bond\_style harmonic/shift/omp command

======================================

bond_style harmonic/shift/omp command

=====================================

Syntax

""""""

.. parsed-literal::

.. code-block:: LAMMPS

   bond_style harmonic/shift

""""""""

.. parsed-literal::

.. code-block:: LAMMPS

   bond_style harmonic/shift

   bond_coeff 5 10.0 0.5 1.0

The *harmonic/shift* bond style is a shifted harmonic bond that uses

the potential

.. image:: Eqs/bond_harmonic_shift.jpg

   :align: center

.. math::

where r0 is the equilibrium bond distance, and rc the critical distance.

The potential is -Umin at r0 and zero at rc. The spring constant is

k = Umin / [ 2 (r0-rc)\^2].

   E = \frac{U_{\text{min}}}{(r_0-r_c)^2} \left[ (r-r_0)^2-(r_c-r_0)^2 \right]

where :math:`r_0` is the equilibrium bond distance, and :math:`r_c` the critical distance.

The potential is :math:`-U_{\text{min}}` at :math:`r0` and zero at :math:`r_c`. The spring constant is

:math:`k = U_{\text{min}} / [ 2 (r_0-r_c)^2]`.

The following coefficients must be defined for each bond type via the

:doc:`bond\_coeff <bond_coeff>` command as in the example above, or in

the data file or restart files read by the :doc:`read\_data <read_data>`

or :doc:`read\_restart <read_restart>` commands:

* Umin (energy)

* :math:`U_{\text{min}}` (energy)

* r0 (distance)

* :math:`r_0` (distance)

* rc (distance)

* :math:`r_c` (distance)

----------

:doc:`bond\_harmonic <bond_harmonic>`

**Default:** none

.. _lws: http://lammps.sandia.gov

.. _ld: Manual.html

.. _lc: Commands_all.html

"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)

:link(ld,Manual.html)

:link(lc,Commands_all.html)

:line

bond_style harmonic/shift command :h3

bond_style harmonic/shift/omp command :h3

[Syntax:]

bond_style harmonic/shift :pre

[Examples:]

bond_style harmonic/shift

bond_coeff 5 10.0 0.5 1.0 :pre

[Description:]

The {harmonic/shift} bond style is a shifted harmonic bond that uses

the potential

:c,image(Eqs/bond_harmonic_shift.jpg)

where r0 is the equilibrium bond distance, and rc the critical distance.

The potential is -Umin at r0 and zero at rc. The spring constant is

k = Umin / \[ 2 (r0-rc)^2\].

The following coefficients must be defined for each bond type via the

"bond_coeff"_bond_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:

Umin (energy) :ul

r0 (distance) :ul

rc (distance) :ul

:line

Styles with a {gpu}, {intel}, {kk}, {omp}, or {opt} suffix are

functionally the same as the corresponding style without the suffix.

They have been optimized to run faster, depending on your available

hardware, as discussed on the "Speed packages"_Speed_packages.html doc

page.  The accelerated styles take the same arguments and should

produce the same results, except for round-off and precision issues.

These accelerated styles are part of the GPU, USER-INTEL, KOKKOS,

USER-OMP and OPT packages, respectively.  They are only enabled if

LAMMPS was built with those packages.  See the "Build

package"_Build_package.html doc page for more info.

You can specify the accelerated styles explicitly in your input script

by including their suffix, or you can use the "-suffix command-line

switch"_Run_options.html when you invoke LAMMPS, or you can use the

"suffix"_suffix.html command in your input script.

See the "Speed packages"_Speed_packages.html doc page for more

instructions on how to use the accelerated styles effectively.

:line

[Restrictions:]

This bond style can only be used if LAMMPS was built with the

USER-MISC package.  See the "Build package"_Build_package.html doc

page for more info.

[Related commands:]

"bond_coeff"_bond_coeff.html, "delete_bonds"_delete_bonds.html,

"bond_harmonic"_bond_harmonic.html

[Default:] none