forked from lijiext/lammps
91 lines
2.8 KiB
Plaintext
91 lines
2.8 KiB
Plaintext
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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 meam/spline :h3
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[Syntax:]
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pair_style meam/spline :pre
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[Examples:]
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pair_style meam/spline
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pair_coeff * * Ti.splinemeam :pre
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[Description:]
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The {meam/spline} style computes pairwise interactions for metals
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using a variant of modified embedded-atom method (MEAM) potentials "(Lenosky)"_#Lenosky. The total
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energy E is given by
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:c,image(spline_meam_formula1.png)
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with the density at atom i
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:c,image(spline_meam_formula2.png)
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where theta_jik is the angle between atoms j, i, and k centered on
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atom i. The five functions Phi, U, rho, f, and g are represented by cubic
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splines.
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The cutoffs and the coefficients for these spline functions are listed
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in a parameter file which is specified by the "pair_coeff"_pair_coeff.html command.
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Parameter files for different elements are
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included in the "potentials" directory of the LAMMPS distribution and have a ".splinemeam" file suffix.
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All of these files are parameterized in terms of LAMMPS "metal units"_units.html.
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IMPORTANT NOTE: The {meam/spline} style currently supports only single-element MEAM potentials.
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The cutoff for spline-based MEAM potentials is
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not set in the pair_style or pair_coeff command; it is specified in
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the potential parameter file.
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Unlike the EAM pair style, which retrieves the atomic mass from the potential file,
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the spline-based MEAM potentials do not include mass information; thus you need to use the "mass"_mass.html
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command to specify it.
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:line
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[Mixing, shift, table, tail correction, restart, rRESPA info]:
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The current version of this pair style does not support multiple element types or mixing.
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It has been designed for pure elements only.
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This pair style does not support the "pair_modify"_pair_modify.html
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shift, table, and tail options.
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The {meam/spline} pair style does not write its information to "binary restart
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files"_restart.html, since it is stored in an external potential parameter file.
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Thus, you need to re-specify the pair_style and pair_coeff commands in
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an input script that reads a restart file.
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The {meam/spline} pair style can only be used via the {pair} keyword of the
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"run_style respa"_run_style.html command. They do not support the
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{inner}, {middle}, {outer} keywords.
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:line
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[Restrictions:]
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This pair style requires the "newton"_newton.html setting to be "on"
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for pair interactions.
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This pair style is only enabled if LAMMPS was built with the USER-MISC package.
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See the "Making LAMMPS"_Section_start.html#start_3 section for more info.
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[Related commands:]
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"pair_coeff"_pair_coeff.html
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[Default:] none
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:line
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:link(Lenosky)
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[(Lenosky)] Lenosky, Sadigh, Alonso, Bulatov, de la Rubia, Kim, Voter, Kress, Modell. Simul. Mater. Sci. Eng. 8, 825 (2000).
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