At last the long awaited EAM has finally been programmed for a Chromium system. For the last 10 days, the program was displaying "nan" as the embedding energy and modified energy values. Tried almost everything to get rid of the error, (i) shifted the entire dimension base from amu(A)2/(fs)2 to eV, but with no avail, (ii) knight.abhi suggested that there's a 0/0 computation somewhere, but accounting for that also proved to be of no avail. Guess what the ridiculous error was: too large a timestep (t=10 fs) which was finally reduced to (t=1 fs) to get the program running correctly.
Another code was run for 20x20x20 system for stability, keeping five boundaries fixed and the top surface open so that the surface shrinks. With this setup the average distance between nearest atoms were found out by considering the 8 closest atoms to each atom, after all the closest atoms were selected using a (r<1.5*r0) criterion and sorted. The average distance after 200.000 fs was computed to be 2.65289503 A, whereas the initial bcc lattice was constructed using r0 = 2.754. So, the system shrinkage is accounted for.
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