forked from lijiext/lammps
59 lines
1.5 KiB
Plaintext
59 lines
1.5 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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improper_style distance command :h3
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[Syntax:]
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improper_style distance
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[Examples:]
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improper_style distance
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improper_coeff 1 80.0 100.0 :pre
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[Description:]
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The {distance} improper style uses the potential
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:c,image(Eqs/improper_dist-1.jpg)
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where d is the distance between the central atom and the plane formed
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by the other three atoms. If the 4 atoms in an improper quadruplet
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(listed in the data file read by the "read_data"_read_data.html
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command) are ordered I,J,K,L then the I-atom is assumed to be the
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central atom.
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:c,image(JPG/improper_distance.jpg)
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Note that defining 4 atoms to interact in this way, does not mean that
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bonds necessarily exist between I-J, J-K, or K-L, as they would in a
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linear dihedral. Normally, the bonds I-J, I-K, I-L would exist for an
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improper to be defined between the 4 atoms.
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The following coefficients must be defined for each improper type via
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the improper_coeff command as in the example above, or in the data
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file or restart files read by the read_data or read_restart commands:
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K_2 (energy/distance^2)
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K_4 (energy/distance^4) :ul
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:line
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[Restrictions:]
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This improper style can only be used if LAMMPS was built with the
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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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[Related commands:]
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"improper_coeff"_improper_coeff.html
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[Default:] none
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