Dear All,
Sorry to bother you (again) with the constraints topic, but I am facing some unexpected troubles with the rhomboid constraint.
I want to put my particles inside a parallelepiped channel along the x-direction.
For that, I was using four wall constraints:
% Planes in z parallel to xy-plane
constraint wall normal 0 0 -1 dist [expr { -($bl*0.5 + $ancho*0.5) }] type 1
constraint wall normal 0 0 1 dist [expr { $bl*0.5 - $ancho*0.5 }] type 1
% Planes in y parallel to yz-plane
constraint wall normal 0 -1 0 dist [expr {-($bl*0.5 + $ancho*0.5) }] type 1
constraint wall normal 0 +1 0 dist [expr { $bl*0.5 - $ancho*0.5 }] type 1
When I run the simulations, the constraint force inside the channel is similar to
this:
# z
constraint: 0.0 0.0 230301.3951708223
constraint: 0.0 0.0 -222545.7573551011
# y
constraint: 0.0 227151.0143805159 0.0
constraint: 0.0 -223949.8044180491 0.0
which I believe are reasonable values. Then I found the rhomboid constraint, thus,
I decided to move and use this suited channel
In my script I have something like this:
part $i pos $posx $posy $posz type 0 fix 0 0 0
inter 0 0 lennard-jones $lj_ener $lj_sigma $lj_rcut $cshift $lj_roff
and
inter 0 1 lj-gen $lj_ener $lj_sigma $lj_rcut $cshift $lj_roff $e1 $e2 $b1 $b2
constraint rhomboid corner 0 $esq $esq a $bl 0 0 b 0 $factor 0 c 0 0 $factor direction -1 type 1
In contrast with the cyIinder and wall constraints, I can visualize correctly the rhomboid channel, but during the simulations the constraint force obtained with the command [constraint force 0] is only along the z-direction. Something like this,
constraint force: 0.0 0.0 -4726.833698873771
I was expecting something similar to what I obtained with the cylinder constraint:
constraint force: 4.614819468504899e-10 -4030.584976737123 3630.226083974555
Does any body has experiencing a similar problem? In fact, my particles inside the rhomboid channel exhibit overlapping with the channel after few integrate steps .
Any suggestion would be greatly appreciated.
Thanks a lot in advance
Salvador