I have some questions to be solved. They are listed as followed.
I used fix heat and fix nph command to add energy to all the Cu atoms in a region. When the temperature reached the melting point, the boundary of the whole system melted first but not the region which energy added in. How to solve it?
When use fix npt/nph command, How can I rescale the box only in the z direction?
Can I get a figure of temperature field with LAMMPS? If not, is there any helpful assistant soft for this question?
I have some questions to be solved. They are listed as followed.
1. I used fix heat and fix nph command to add energy to all the Cu atoms in
a region. When the temperature reached the melting point, the boundary of
the whole system melted first but not the region which energy added in. How
to solve it?
When a real material melts, where do you think the melting start? Is
it easier to nucleate a liquid phase in a perfect region or in a
region containing defects and heterogeneities? If your setup and your
potential are good, the system may be doing something very physical.
Thank you.I have done the same thing as the manual says.
The manual says,"For example, if the y keyword is used, the y-box length will change. "
I wrote the in.doc as followed,
units metal
……
……
region 1 block 17 127 17 27 -9 1 units box
group laser region 1
fix 2 all heat 10000 2 region 1
fix 3 all nph z 1.0 1.0 100(dilate laser)
……
……
dump 1 all custom 100 copper.lammpstrj id type xu yu zu
run 1000000
But it still scaled the x-box and y-box length.What’s the matter?
I used VMD to have a look at the coordinate of the atoms. They moved out of box in x or y direction more than half of the box. If this problem did not cause by fix npt/nph, is it related to fix heat canmmand?
dump 1 all custom 100 copper.lammpstrj id type xu yu zu
which is unwrapped coords, which may end up far outside the
box. VMD can viz that in different ways. Look in the dump
file to see what LAMMPS says the box dimensions are at
each timestep.