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git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@9777 f3b2605a-c512-4ea7-a41b-209d697bcdaa

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sjplimp
2013-04-16 18:40:05 +00:00
parent 3d850b6cc3
commit e7e149cbdc
4 changed files with 38 additions and 22 deletions
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28
doc/fix_wall.html
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@ -78,8 +78,8 @@ wall-particle interactions depends on the style.
</P>
<CENTER><IMG SRC = "Eqs/pair_lj.jpg">
</CENTER>
<P>For style <I>wall/colloid</I>, the energy E is given by an integrated form of
the <A HREF = "pair_colloid.html">pair_style colloid</A> potential:
<P>For style <I>wall/colloid</I>, the energy E is given by an integrated form
of the <A HREF = "pair_colloid.html">pair_style colloid</A> potential:
</P>
<CENTER><IMG SRC = "Eqs/fix_wall_colloid.jpg">
</CENTER>
@ -126,18 +126,26 @@ computes particle-particle interactions.
half-lattice of Lennard-Jones 12/6 particles. The <I>wall/lj126</I>
interaction is effectively a harder, more repulsive wall interaction.
</P>
<P>For the <I>wall/colloid</I> style, <I>epsilon</I> is effectively a Hamaker
constant with energy units for the colloid-wall interaction, <I>R</I> is
the radius of the colloid particle, <I>D</I> is the distance from the
surface of the colloid particle to the wall (r-R), and <I>sigma</I> is the
size of a constituent LJ particle inside the colloid particle. Note
that the cutoff distance Rc in this case is the distance from the
colloid particle center to the wall.
<P>For the <I>wall/colloid</I> style, <I>R</I> is the radius of the colloid
particle, <I>D</I> is the distance from the surface of the colloid particle
to the wall (r-R), and <I>sigma</I> is the size of a constituent LJ
particle inside the colloid particle and wall. Note that the cutoff
distance Rc in this case is the distance from the colloid particle
center to the wall. The prefactor <I>epsilon</I> can be thought of as an
effective Hamaker constant with energy units for the strength of the
colloid-wall interaction. More specifically, the <I>epsilon</I> pre-factor
= 4 * pi^2 * rho_wall * rho_colloid * epsilon * sigma^6, where epsilon
and sigma are the LJ parameters for the constituent LJ
particles. Rho_wall and rho_colloid are the number density of the
constituent particles, in the wall and colloid respectively, in units
of 1/volume.
</P>
<P>The <I>wall/colloid</I> interaction is derived by integrating over
constituent LJ particles of size <I>sigma</I> within the colloid particle
and a 3d half-lattice of Lennard-Jones 12/6 particles of size <I>sigma</I>
in the wall.
in the wall. As mentioned in the preceeding paragraph, the density of
particles in the wall and colloid can be different, as specified by
the <I>epsilon</I> pre-factor.
</P>
<P>For the <I>wall/harmonic</I> style, <I>epsilon</I> is effectively the spring
constant K, and has units (energy/distance^2). The input parameter

28
doc/fix_wall.txt
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@ -64,8 +64,8 @@ For style {wall/lj126}, the energy E is given by the 12/6 potential:
:c,image(Eqs/pair_lj.jpg)
For style {wall/colloid}, the energy E is given by an integrated form of
the "pair_style colloid"_pair_colloid.html potential:
For style {wall/colloid}, the energy E is given by an integrated form
of the "pair_style colloid"_pair_colloid.html potential:
:c,image(Eqs/fix_wall_colloid.jpg)
@ -112,18 +112,26 @@ The {wall/lj93} interaction is derived by integrating over a 3d
half-lattice of Lennard-Jones 12/6 particles. The {wall/lj126}
interaction is effectively a harder, more repulsive wall interaction.
For the {wall/colloid} style, {epsilon} is effectively a Hamaker
constant with energy units for the colloid-wall interaction, {R} is
the radius of the colloid particle, {D} is the distance from the
surface of the colloid particle to the wall (r-R), and {sigma} is the
size of a constituent LJ particle inside the colloid particle. Note
that the cutoff distance Rc in this case is the distance from the
colloid particle center to the wall.
For the {wall/colloid} style, {R} is the radius of the colloid
particle, {D} is the distance from the surface of the colloid particle
to the wall (r-R), and {sigma} is the size of a constituent LJ
particle inside the colloid particle and wall. Note that the cutoff
distance Rc in this case is the distance from the colloid particle
center to the wall. The prefactor {epsilon} can be thought of as an
effective Hamaker constant with energy units for the strength of the
colloid-wall interaction. More specifically, the {epsilon} pre-factor
= 4 * pi^2 * rho_wall * rho_colloid * epsilon * sigma^6, where epsilon
and sigma are the LJ parameters for the constituent LJ
particles. Rho_wall and rho_colloid are the number density of the
constituent particles, in the wall and colloid respectively, in units
of 1/volume.
The {wall/colloid} interaction is derived by integrating over
constituent LJ particles of size {sigma} within the colloid particle
and a 3d half-lattice of Lennard-Jones 12/6 particles of size {sigma}
in the wall.
in the wall. As mentioned in the preceeding paragraph, the density of
particles in the wall and colloid can be different, as specified by
the {epsilon} pre-factor.
For the {wall/harmonic} style, {epsilon} is effectively the spring
constant K, and has units (energy/distance^2). The input parameter

2
doc/pair_eff.html
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@ -37,7 +37,7 @@ pair_style eff/cut 40.0 ecp 1 Si 3 C
pair_coeff * *
pair_coeff 2 2 20.0
pair_coeff 1 s 0.320852 2.283269 0.814857
pair_coeff 3 22.721015 0.728733 1.103199 17.695345 6.693621
pair_coeff 3 p 22.721015 0.728733 1.103199 17.695345 6.693621
</PRE>
<P><B>Description:</B>
</P>

2
doc/units.html
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@ -138,7 +138,7 @@ by the number of atoms, i.e. energy/atom. This can be changed via the
<LI>time = femtoseconds
<LI>energy = Hartrees
<LI>velocity = Bohr/atomic time units [1.03275e-15 seconds]
<LI>force = Hartrees*Bohr
<LI>force = Hartrees/Bohr
<LI>temperature = degrees K
<LI>pressure = Pascals
<LI>charge = multiple of electron charge (+1.0 is a proton)