2011-08-09 06:50:30 +08:00
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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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bond_style harmonic/shift command :h3
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2011-12-01 23:35:32 +08:00
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bond_style harmonic/shift/omp command :h3
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2011-08-09 06:50:30 +08:00
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[Syntax:]
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bond_style harmonic/shift :pre
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[Examples:]
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bond_style harmonic/shift
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bond_coeff 5 10.0 0.5 1.0 :pre
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[Description:]
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The {harmonic/shift} bond style is a shifted harmonic bond that uses
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the potential
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:c,image(Eqs/bond_harmonic_shift.jpg)
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where r0 is the equilibrium bond distance, and rc the critical distance.
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The potential is -Umin at r0 and zero at rc. The spring constant is
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k = Umin / \[ 2 (r0-rc)^2\].
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The following coefficients must be defined for each bond type via the
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"bond_coeff"_bond_coeff.html command as in the example above, or in
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the data file or restart files read by the "read_data"_read_data.html
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or "read_restart"_read_restart.html commands:
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Umin (energy) :ul
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r0 (distance) :ul
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rc (distance) :ul
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2011-12-01 23:35:32 +08:00
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:line
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Styles with a {cuda}, {gpu}, {omp}, or {opt} suffix are functionally
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the same as the corresponding style without the suffix. They have
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been optimized to run faster, depending on your available hardware,
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as discussed in "this section"_Section_accelerate.html of the manual.
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The accelerated styles take the same arguments and should produce the
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same results, except for round-off and precision issues.
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These accelerated styles are part of the USER-CUDA, GPU, USER-OMP and OPT
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packages, respectively. They are only enabled if LAMMPS was built with
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those packages. See the "Making LAMMPS"_Section_start.html#start_3
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section for more info.
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You can specify the accelerated styles explicitly in your input script
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by including their suffix, or you can use the "-suffix command-line
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switch"_Section_start.html#start_6 when you invoke LAMMPS, or you can
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use the "suffix"_suffix.html command in your input script.
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See "this section"_Section_accelerate.html of the manual for more
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instructions on how to use the accelerated styles effectively.
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:line
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2011-08-09 06:50:30 +08:00
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[Restrictions:]
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This bond style can only be used if LAMMPS was built with the
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2011-08-27 02:53:00 +08:00
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USER-MISC package. See the "Making LAMMPS"_Section_start.html#start_3
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section for more info on packages.
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2011-08-09 06:50:30 +08:00
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[Related commands:]
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"bond_coeff"_bond_coeff.html, "delete_bonds"_delete_bonds.html,
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"bond_harmonic"_bond_harmonic.html
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[Default:] none
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