65 lines
2.0 KiB
Plaintext
65 lines
2.0 KiB
Plaintext
"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_write command :h3
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[Syntax:]
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bond_write btype N inner outer file keyword itype jtype :pre
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btype = bond types
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N = # of values
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inner,outer = inner and outer bond length (distance units)
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file = name of file to write values to
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keyword = section name in file for this set of tabulated values
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itype,jtype = 2 atom types (optional)
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:ul
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[Examples:]
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bond_write 1 500 0.5 3.5 table.txt Harmonic_1
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bond_write 3 1000 0.1 6.0 table.txt Morse :pre
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[Description:]
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Write energy and force values to a file as a function of distance for
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the currently defined bond potential. This is useful for plotting the
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potential function or otherwise debugging its values. If the file
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already exists, the table of values is appended to the end of the file
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to allow multiple tables of energy and force to be included in one
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file.
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The energy and force values are computed at distances from inner to
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outer for 2 interacting atoms forming a bond of type btype, using the
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appropriate "bond_coeff"_bond_coeff.html coefficients. N evenly spaced
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distances are used.
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For example, for N = 7, inner = 1.0, and outer = 4.0,
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values are computed at r = 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0.
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The file is written in the format used as input for the
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"bond_style"_bond_style.html {table} option with {keyword} as the
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section name. Each line written to the file lists an index number
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(1-N), a distance (in distance units), an energy (in energy units),
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and a force (in force units).
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[Restrictions:]
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All force field coefficients for bond and other kinds of interactions
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must be set before this command can be invoked.
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Due to how the bond force is computed, an inner value > 0.0 must
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be specified even if the potential has a finite value at r = 0.0.
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[Related commands:]
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"bond_style table"_bond_table.html,
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"bond_style"_bond_style.html, "bond_coeff"_bond_coeff.html
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[Default:] none
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