forked from lijiext/lammps
65 lines
2.3 KiB
Plaintext
65 lines
2.3 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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dihedral_style hybrid command :h3
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[Syntax:]
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dihedral_style hybrid style1 style2 ... :pre
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style1,style2 = list of one or more dihedral styles :ul
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[Examples:]
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dihedral_style hybrid harmonic helix
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dihedral_coeff 1 harmonic 6.0 1 3
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dihedral_coeff 2 helix 10 10 10 :pre
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[Description:]
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The {hybrid} style enables the use of multiple dihedral styles in one
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simulation. An dihedral style is assigned to each dihedral type. For
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example, dihedrals in a polymer flow (of dihedral type 1) could be
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computed with a {harmonic} potential and dihedrals in the wall
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boundary (of dihedral type 2) could be computed with a {helix}
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potential. The assignment of dihedral type to style is made via the
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"dihedral_coeff"_dihedral_coeff.html command or in the data file.
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In the dihedral_coeff command, the first coefficient sets the dihedral
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style and the remaining coefficients are those appropriate to that
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style. In the example above, the 2 dihedral_coeff commands would set
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dihedrals of dihedral type 1 to be computed with a {harmonic}
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potential with coefficients 80.0, 1.2 for K, d, n. Dihedral type 2
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would be computed with a {helix} potential with coefficients 10.0,
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10.0, 10.0 for A, B, C.
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If the dihedral {class2} potential is one of the hybrid styles, it
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requires additional MiddleBondTorsion, EndBondTorsion, AngleTorsion,
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AngleAngleTorsion, and BondBond13 coefficients be specified in the
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data file. These lines must also have an additional "class2" argument
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added after the dihedral type. For dihedral types which are assigned
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to other hybrid styles, use the style name (e.g. "harmonic")
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appropriate to that style. The MiddleBondTorsion, etc coeffs for that
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dihedral type will then be ignored.
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A dihedral style of {none} can be specified as an argument to
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dihedral_style hybrid and the corresponding dihedral_coeff commands,
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if you desire to turn off certain dihedral types.
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[Restrictions:]
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This dihedral style can only be used if LAMMPS was built with the
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"molecular" package (which it is by default). See the "Making
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LAMMPS"_Section_start.html#2_3 section for more info on packages.
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[Related commands:]
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"dihedral_coeff"_dihedral_coeff.html
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[Default:] none
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