lammps/doc/pair_meam_spline.txt

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pair_style meam/spline :h3

[Syntax:]

pair_style meam/spline :pre

[Examples:]

pair_style meam/spline
pair_coeff * * Ti.meam.spline :pre

[Description:]

The {meam/spline} style computes pairwise interactions for metals
using a variant of modified embedded-atom method (MEAM) potentials
"(Lenosky)"_#Lenosky.  The total energy E is given by

:c,image(Eqs/pair_meam_spline_1.png)

with the density at atom i

:c,image(Eqs/pair_meam_spline_2.png)

where theta_jik is the angle between atoms j, i, and k centered on
atom i. The five functions Phi, U, rho, f, and g are represented by
cubic splines.

The cutoffs and the coefficients for these spline functions are listed
in a parameter file which is specified by the
"pair_coeff"_pair_coeff.html command.  Parameter files for different
elements are included in the "potentials" directory of the LAMMPS
distribution and have a ".meam.spline" file suffix.  All of these
files are parameterized in terms of LAMMPS "metal units"_units.html.

Note that unlike for other potentials, cutoffs for spline-based MEAM
potentials are not set in the pair_style or pair_coeff command; they
are specified in the potential files themselves.

Unlike the EAM pair style, which retrieves the atomic mass from the
potential file, the spline-based MEAM potentials do not include mass
information; thus you need to use the "mass"_mass.html command to
specify it.

Only a single pair_coeff command is used with the {meam/spline} style
which specifies the spline-based MEAM potential file:

meam/spline potential file :ul

IMPORTANT NOTE: The {meam/spline} style currently supports only
single-element MEAM potentials.  Thus it cannot be used with
"pair_style hybrid"_pair_hybrid.html command, and with a NULL syntax
in the pair_coeff command, as used by other many-body potentials, to
determine what subset of atom types to apply the potential to.

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[Mixing, shift, table, tail correction, restart, rRESPA info]:

The current version of this pair style does not support multiple
element types or mixing.  It has been designed for pure elements only.

This pair style does not support the "pair_modify"_pair_modify.html
shift, table, and tail options.

The {meam/spline} pair style does not write its information to "binary
restart files"_restart.html, since it is stored in an external
potential parameter file.  Thus, you need to re-specify the pair_style
and pair_coeff commands in an input script that reads a restart file.

The {meam/spline} pair style can only be used via the {pair} keyword of the
"run_style respa"_run_style.html command.  They do not support the
{inner}, {middle}, {outer} keywords.

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[Restrictions:]

This pair style requires the "newton"_newton.html setting to be "on"
for pair interactions.

This pair style is only enabled if LAMMPS was built with the USER-MISC
package.  See the "Making LAMMPS"_Section_start.html#start_3 section
for more info.

[Related commands:]

"pair_coeff"_pair_coeff.html, "pair_style meam"_pair_meam.html

[Default:] none

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:link(Lenosky)
[(Lenosky)] Lenosky, Sadigh, Alonso, Bulatov, de la Rubia, Kim, Voter,
Kress, Modelling Simulation Materials Science Enginerring, 8, 825
(2000).