I am attaching The modified Monte Carlo code for energy minimization (from lammps example) used on a known stable Cristobalite Structure for Quartz. The code gives the following result corresponding to the attached input file and parameters:
Note that the Minimum energy of perfect lattice is corresponding to the stable energy of the already optimized structure. On moving the original atom locations in the input file by 0.01 on multiple atom locations , the code gives the same minimum perfect lattice energy. Unfortunately, this isnt true for displacement of atoms >0.01 A. I have been attempting to display the atom locations corresponding to the minimum energy of the perfect lattice using " “write_dump all xyz system.xyz modify sort id” &". The above line keeps displaying the final location of the lattice corresponding to the final energy -7354 as shown above, instead of -5421. This claim can further be verified by the xyz values and the video generated. Please provide guidance on where to put the xyz location generating command to output the right atom locations.
In order to find the minimum energy upon annealing is increasing kT value sufficient or something else needed?
PS- potential used in this code is corresponding to the attached paper.
cristobalite (beta) Coordinates.txt (2.93 KB)
in.quartz_GP_Si (3.84 KB)
data.G8SiO2 (982 Bytes)
Guillot_Paper.pdf (606 KB)
system.xyz (667 Bytes)