lammps/doc/bond_morse.txt

"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)

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bond_style morse command :h3
bond_style morse/omp command :h3

[Syntax:]

bond_style morse :pre

[Examples:]

bond_style morse
bond_coeff 5 1.0 2.0 1.2 :pre

[Description:]

The {morse} bond style uses the potential

:c,image(Eqs/bond_morse.jpg)

where r0 is the equilibrium bond distance, alpha is a stiffness
parameter, and D determines the depth of the potential well.

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:

D (energy)
alpha (inverse distance)
r0 (distance) :ul

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Styles with a {cuda}, {gpu}, {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 "this section"_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 USER-CUDA, GPU, 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 "this section"_Section_accelerate.html of the manual for more
instructions on how to use the accelerated styles effectively.

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[Restrictions:]

This bond style can only be used if LAMMPS was built with the
MOLECULAR package (which it is by default).  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

[Default:] none