git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@242 f3b2605a-c512-4ea7-a41b-209d697bcdaa

This commit is contained in:
sjplimp 2007-01-17 20:23:28 +00:00
parent 9c95030827
commit 30a7fcd23d
4 changed files with 58 additions and 16 deletions

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@ -60,8 +60,8 @@ potentials.
<P>Stillinger-Weber files in the <I>potentials</I> directory of the LAMMPS
distribution have a ".sw" suffix. Lines that are not blank or
comments (starting with #) define parameters for a triplet of
elements. The parameters in a single entry correspond to coefficients
in the formula above:
elements. The parameters in a single entry correspond to the two-body
and three-body coefficients in the formula above:
</P>
<UL><LI>element 1 (the center atom in a 3-body interaction)
<LI>element 2
@ -89,8 +89,18 @@ simulation; LAMMPS ignores those entries.
entries (for SiSiSi, SiSiC, SiCSi, SiCC, CSiSi, CSiC, CCSi, CCC), that
specify SW parameters for all permutations of the two elements
interacting in three-body configurations. Thus for 3 elements, 27
entries would be required, etc. Note that due to symmetries, some
parameters will typically be the same in multiple entries.
entries would be required, etc.
</P>
<P>As annotated above, the first element in the entry is the center atom
in a three-body interaction. Thus an entry for SiCC means a Si atom
with 2 C atoms as neighbors. By symmetry, three-body parameters for
SiCSi and SiSiC entries should be the same. Two-body parameters for
an interaction come from the entry where the 2nd element is repeated.
Thus the two-body parameters for Si interacting with C, comes from the
SiCC entry. Again by symmetry, the two-body parameters in the SiCC
and CSiSi entries should thus be the same. Two-body parameters in
entries whose 2nd and 3rd element are different (e.g. SiCSi) are
ignored.
</P>
<P><B>Restrictions:</B>
</P>

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@ -57,8 +57,8 @@ potentials.
Stillinger-Weber files in the {potentials} directory of the LAMMPS
distribution have a ".sw" suffix. Lines that are not blank or
comments (starting with #) define parameters for a triplet of
elements. The parameters in a single entry correspond to coefficients
in the formula above:
elements. The parameters in a single entry correspond to the two-body
and three-body coefficients in the formula above:
element 1 (the center atom in a 3-body interaction)
element 2
@ -86,8 +86,18 @@ For a single-element simulation, only a single entry is required
entries (for SiSiSi, SiSiC, SiCSi, SiCC, CSiSi, CSiC, CCSi, CCC), that
specify SW parameters for all permutations of the two elements
interacting in three-body configurations. Thus for 3 elements, 27
entries would be required, etc. Note that due to symmetries, some
parameters will typically be the same in multiple entries.
entries would be required, etc.
As annotated above, the first element in the entry is the center atom
in a three-body interaction. Thus an entry for SiCC means a Si atom
with 2 C atoms as neighbors. By symmetry, three-body parameters for
SiCSi and SiSiC entries should be the same. Two-body parameters for
an interaction come from the entry where the 2nd element is repeated.
Thus the two-body parameters for Si interacting with C, comes from the
SiCC entry. Again by symmetry, the two-body parameters in the SiCC
and CSiSi entries should thus be the same. Two-body parameters in
entries whose 2nd and 3rd element are different (e.g. SiCSi) are
ignored.
[Restrictions:]

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@ -64,8 +64,8 @@ parameters in a single entry correspond to coefficients in the formula
above:
</P>
<UL><LI>element 1 (the center atom in a 3-body interaction)
<LI>element 2
<LI>element 3
<LI>element 2 (the atom bonded to the center atom)
<LI>element 3 (the atom influencing the 1-2 bond in a bond-order sense)
<LI>lambda3 (1/distance units)
<LI>c
<LI>d
@ -91,8 +91,19 @@ ignores those entries.
entries (for SiSiSi, SiSiC, SiCSi, SiCC, CSiSi, CSiC, CCSi, CCC), that
specify Tersoff parameters for all permutations of the two elements
interacting in three-body configurations. Thus for 3 elements, 27
entries would be required, etc. Note that due to symmetries, some
parameters will typically be the same in multiple entries.
entries would be required, etc.
</P>
<P>As annotated above, the first element in the entry is the center atom
in a three-body interaction and it is bonded to the 2nd atom and the
bond is influenced by the 3rd atom. Thus an entry for SiCC means Si
bonded to a C with another C atom influencing the bond. Thus
three-body parameters for SiCSi and SiSiC entries will not, in
general, be the same. Two-body parameters for an interaction come
from the entry where the 2nd element is repeated. Thus the two-body
parameters for Si interacting with C, comes from the SiCC entry. By
symmetry, the two-body parameters in the SiCC and CSiSi entries should
thus be the same. Two-body parameters in entries whose 2nd and 3rd
element are different (e.g. SiCSi) are ignored.
</P>
<P><B>Restrictions:</B>
</P>

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@ -61,8 +61,8 @@ parameters in a single entry correspond to coefficients in the formula
above:
element 1 (the center atom in a 3-body interaction)
element 2
element 3
element 2 (the atom bonded to the center atom)
element 3 (the atom influencing the 1-2 bond in a bond-order sense)
lambda3 (1/distance units)
c
d
@ -88,8 +88,19 @@ For a single-element simulation, only a single entry is required
entries (for SiSiSi, SiSiC, SiCSi, SiCC, CSiSi, CSiC, CCSi, CCC), that
specify Tersoff parameters for all permutations of the two elements
interacting in three-body configurations. Thus for 3 elements, 27
entries would be required, etc. Note that due to symmetries, some
parameters will typically be the same in multiple entries.
entries would be required, etc.
As annotated above, the first element in the entry is the center atom
in a three-body interaction and it is bonded to the 2nd atom and the
bond is influenced by the 3rd atom. Thus an entry for SiCC means Si
bonded to a C with another C atom influencing the bond. Thus
three-body parameters for SiCSi and SiSiC entries will not, in
general, be the same. Two-body parameters for an interaction come
from the entry where the 2nd element is repeated. Thus the two-body
parameters for Si interacting with C, comes from the SiCC entry. By
symmetry, the two-body parameters in the SiCC and CSiSi entries should
thus be the same. Two-body parameters in entries whose 2nd and 3rd
element are different (e.g. SiCSi) are ignored.
[Restrictions:]