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@ -491,17 +491,21 @@ There are several options for outputting atom coordinates. The {x},
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appropriate distance "units"_units.html (Angstroms, sigma, etc). Use
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appropriate distance "units"_units.html (Angstroms, sigma, etc). Use
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{xs}, {ys}, {zs} if you want the coordinates "scaled" to the box size,
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{xs}, {ys}, {zs} if you want the coordinates "scaled" to the box size,
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so that each value is 0.0 to 1.0. If the simulation box is triclinic
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so that each value is 0.0 to 1.0. If the simulation box is triclinic
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(tilted), then all atom coords will still be between 0.0 and 1.0. Use
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(tilted), then all atom coords will still be between 0.0 and 1.0.
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{xu}, {yu}, {zu} if you want the coordinates "unwrapped" by the image
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I.e. actual unscaled (x,y,z) = xs*A + ys*B + zs*C, where (A,B,C) are
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flags for each atom. Unwrapped means that if the atom has passed thru
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the non-orthogonal vectors of the simulation box edges, as discussed
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a periodic boundary one or more times, the value is printed for what
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in "Section howto 6.12"_Section_howto.html#howto_12.
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the coordinate would be if it had not been wrapped back into the
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periodic box. Note that using {xu}, {yu}, {zu} means that the
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Use {xu}, {yu}, {zu} if you want the coordinates "unwrapped" by the
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coordinate values may be far outside the box bounds printed with the
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image flags for each atom. Unwrapped means that if the atom has
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snapshot. Using {xsu}, {ysu}, {zsu} is similar to using {xu}, {yu}, {zu},
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passed thru a periodic boundary one or more times, the value is
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except that the unwrapped coordinates are scaled by the box size. Atoms
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printed for what the coordinate would be if it had not been wrapped
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that have passed through a periodic boundary will have the corresponding
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back into the periodic box. Note that using {xu}, {yu}, {zu} means
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cooordinate increased or decreased by 1.0.
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that the coordinate values may be far outside the box bounds printed
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with the snapshot. Using {xsu}, {ysu}, {zsu} is similar to using
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{xu}, {yu}, {zu}, except that the unwrapped coordinates are scaled by
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the box size. Atoms that have passed through a periodic boundary will
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have the corresponding cooordinate increased or decreased by 1.0.
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The image flags can be printed directly using the {ix}, {iy}, {iz}
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The image flags can be printed directly using the {ix}, {iy}, {iz}
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attributes. For periodic dimensions, they specify which image of the
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attributes. For periodic dimensions, they specify which image of the
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@ -1,72 +0,0 @@
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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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pair_style dpd/conservative command :h3
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[Syntax:]
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pair_style dpd/conservative cutoff :pre
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cutoff = global cutoff for DPD interactions (distance units) :ul
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[Examples:]
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pair_style dpd/conservative 2.5
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pair_coeff * * 3.0 2.5
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pair_coeff 1 1 3.0 :pre
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[Description:]
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Style {dpd/conservative} computes the conservative force for
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dissipative particle dynamics (DPD). The conservative force on atom I
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due to atom J is given by
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:c,image(Eqs/pair_dpd_conservative.jpg)
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where the weighting factor, omega_ij, varies between 0 and 1, and is
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chosen to have the following functional form:
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:c,image(Eqs/pair_dpd_omega.jpg)
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where Rij is a unit vector in the direction Ri - Rj, and Rc is the
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cutoff. Note that alternative definitions of the weighting function
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exist, but would have to be implemented as a separate pair style
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command.
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Style {dpd/conservative} differs from the other dpd styles in that the
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dissipative and random forces are not computed within the pair style.
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For style {dpd/conservative}, the pairwise energy is due only to the
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conservative force term Fc, and is shifted to be zero at the cutoff
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distance Rc. The pairwise virial is calculated using only the
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conservative term.
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Style {dpd/conservative} requires the following coefficients to be
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defined for each pair of atoms types via the
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"pair_coeff"_pair_coeff.html command as in the examples 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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A (force units)
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cutoff (distance units) :ul
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The last coefficient is optional. If not specified, the global DPD
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cutoff is used.
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:line
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[Restrictions:]
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The pair style {dpd/conservative} is only available if LAMMPS is built
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with the USER-DPD package.
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[Related commands:]
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"pair_coeff"_pair_coeff.html, "pair_dpd"_pair_dpd.html
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[Default:] none
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