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change order of morse style wall potential parameters to be consistent with pair morse and bond morse

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This commit is contained in:
Axel Kohlmeyer
2019-08-20 11:27:29 -04:00
parent 47533bc526
commit 3d9e737a19
2 changed files with 34 additions and 27 deletions
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35
doc/src/fix_wall_region.txt
View File

@ -10,24 +10,24 @@ fix wall/region command :h3
[Syntax:]
fix ID group-ID wall/region region-ID style epsilon sigma cutoff args ... :pre
fix ID group-ID wall/region region-ID style args ... cutoff :pre
ID, group-ID are documented in "fix"_fix.html command :ulb,l
wall/region = style name of this fix command :l
region-ID = region whose boundary will act as wall :l
style = {lj93} or {lj126} or {lj1043} or {morse} or {colloid} or {harmonic} :l
epsilon = strength factor for wall-particle interaction (energy or energy/distance^2 units) :l
sigma = size factor for wall-particle interaction (distance units) :l
cutoff = distance from wall at which wall-particle interaction is cut off (distance units) :l
args = :l
alpha (width parameter), if style = {morse}
{none}, if style = {lj93/lj126/lj1043/colloid/harmonic} :pre
epsilon = strength factor for wall-particle interaction (energy or energy/distance^2 units)
alpha (width parameter), only if style = {morse}
sigma = size factor for wall-particle interaction (distance units) :pre
cutoff = distance from wall at which wall-particle interaction is cut off (distance units) :l
:ule
[Examples:]
fix wall all wall/region mySphere lj93 1.0 1.0 2.5
fix wall all wall/region box_top morse 1.0 1.0 3.0 1.5 :pre
fix wall all wall/region mySphere harmonic 1.0 0.0 2.5
fix wall all wall/region box_top morse 1.0 1.0 1.5 3.0 :pre
[Description:]
@ -121,27 +121,28 @@ For style {wall/lj1043}, the energy E is given by the 10/4/3 potential:
:c,image(Eqs/fix_wall_lj1043.jpg)
For style {wall/morse}, the energy E is given by the Morse potential:
:c,image(Eqs/pair_morse.jpg)
where {r_0 = sigma} and {D_0 = epsilon}.
For style {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)
For style {wall/harmonic}, the energy E is given by a harmonic spring
potential:
potential (the distance parameter is ignored):
:c,image(Eqs/fix_wall_harmonic.jpg)
For style {wall/morse}, the energy E is given by the Morse potential:
:c,image(Eqs/pair_morse.jpg)
Unlike other styles, this requires three parameters ({D_0}, {alpha}, {r_0}
in this order) instead of two like for the other wall styles.
In all cases, {r} is the distance from the particle to the region
surface, and Rc is the {cutoff} distance at which the particle and
surface no longer interact. The energy of the wall potential is
shifted so that the wall-particle interaction energy is 0.0 at the
cutoff distance.
surface no longer interact. The cutoff is always the last argument.
The energy of the wall potential is shifted so that the wall-particle
interaction energy is 0.0 at the cutoff distance.
For a full description of these wall styles, see fix_style
"wall"_fix_wall.html

26
src/fix_wall_region.cpp
View File

@ -28,7 +28,7 @@ using namespace LAMMPS_NS;
using namespace FixConst;
using namespace MathConst;
enum{LJ93,LJ126,LJ1043,MORSE,COLLOID,HARMONIC};
enum{LJ93,LJ126,LJ1043,COLLOID,HARMONIC,MORSE};
/* ---------------------------------------------------------------------- */
@ -60,25 +60,31 @@ FixWallRegion::FixWallRegion(LAMMPS *lmp, int narg, char **arg) :
if (strcmp(arg[4],"lj93") == 0) style = LJ93;
else if (strcmp(arg[4],"lj126") == 0) style = LJ126;
else if (strcmp(arg[4],"lj1043") == 0) style = LJ1043;
else if (strcmp(arg[4],"morse") == 0) style = MORSE;
else if (strcmp(arg[4],"colloid") == 0) style = COLLOID;
else if (strcmp(arg[4],"harmonic") == 0) style = HARMONIC;
else if (strcmp(arg[4],"morse") == 0) style = MORSE;
else error->all(FLERR,"Illegal fix wall/region command");
if (style != COLLOID) dynamic_group_allow = 1;
epsilon = force->numeric(FLERR,arg[5]);
sigma = force->numeric(FLERR,arg[6]);
cutoff = force->numeric(FLERR,arg[7]);
if (style == MORSE) {
if (narg != 9)
error->all(FLERR,"Illegal fix wall/region command");
else
alpha = force->numeric(FLERR,arg[8]);
} else if (narg != 8)
epsilon = force->numeric(FLERR,arg[5]);
alpha = force->numeric(FLERR,arg[6]);
sigma = force->numeric(FLERR,arg[7]);
cutoff = force->numeric(FLERR,arg[8]);
} else {
if (narg != 8)
error->all(FLERR,"Illegal fix wall/region command");
epsilon = force->numeric(FLERR,arg[5]);
sigma = force->numeric(FLERR,arg[6]);
cutoff = force->numeric(FLERR,arg[7]);
}
if (cutoff <= 0.0) error->all(FLERR,"Fix wall/region cutoff <= 0.0");
eflag = 0;
@ -297,7 +303,7 @@ void FixWallRegion::post_force(int vflag)
/* ---------------------------------------------------------------------- */
void FixWallRegion::post_force_respa(int vflag, int ilevel, int iloop)
void FixWallRegion::post_force_respa(int vflag, int ilevel, int /* iloop */)
{
if (ilevel == ilevel_respa) post_force(vflag);
}