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lammps/doc/src/bond_harmonic_shift.txt
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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)
: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 in "Section 5"_Section_accelerate.html
of the manual. 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 "Making
LAMMPS"_Section_start.html#start_3 section 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"_Section_start.html#start_6 when you invoke LAMMPS, or you can
use the "suffix"_suffix.html command in your input script.
See "Section 5"_Section_accelerate.html of the manual 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 "Making LAMMPS"_Section_start.html#start_3
section for more info on packages.
[Related commands:]
"bond_coeff"_bond_coeff.html, "delete_bonds"_delete_bonds.html,
"bond_harmonic"_bond_harmonic.html
[Default:] none
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