Basic Nickel simulation

Input script

units metal #<What are the units you will use to specify various things in the input file?
boundary p p p #<Specify periodic boundary condition are needed in all three faces of the simulation box>
atom_style atomic #<What style of atoms is to be used in the simulation>
log logfile.txt #<Write the log file to this text file. All thermodynamic information applicable to the entire system>
#================================================
region forbox block 0 35.2 0 35.2 0 35.2 units box
#<Refers to an abstract geometric region of space. units box refers to the fact that the size of the box is specified in the units as given in the units command. The name "forbox" refers to the region ID so that you can refer to it somewhere else in this input script.>
create_box 1 forbox #<Create the box>

Log file of Nickel simulation

I just wanted to show you guys how a log file looks like. As I mentioned earlier, the log file has global values(values which correspond to the entire simulation box), plays a crucial role in post-processing of data. Visit my Input and output files blog page, where I have given a brief explanation of this. Here I am going to show you the log file generated by the previous Nickel simulation. Hope this gives you an idea of how a log file looks like.

Log File

#================================================
region forbox block 0 35.2 0 35.2 0 35.2 units box
#<Refers to an abstract geometric region of space. units box refers to the fact that the size of the box is specified in the units as given in the units command. The name "forbox" refers to the region ID so that you can refer to it somewhere else in this input script.>
create_box 1 forbox #<Create the box>
Created orthogonal box = (0 0 0) to (35.2 35.2 35.2)
  1 by 1 by 1 MPI processor grid

Verifying lattice constant-Nickel

Lattice constant for Nickel is 3.52 angstrom. But how do we know it is correct? There is a computational technique using which we can verify the lattice constant values. Let's see how.

Generally, every atom, molecule, crystal whatever it is, tend to have the lowest potential energy state, possible for that. That's nature. This potential energy of atoms depends directly on the lattice constant corresponding to its crystal structure. So the crystal will have lattice constant which corresponds to the lowest potential energy. Here I am going to calculate the potential energy of nickel for various lattice constants. 

Nickel sphere collision

In this blog, I have made a simulation on which two nickel spheres colloid each other. Through this simulation, I have introduces some new commands. Have a look at them.

Input script

#------------------ Setup the simulation -------------------------
log                   log.in
dimension       3
units                metal
atom_style      atomic
boundary         p p p