EAM DYNAMO setfl

Format

HEADER INFORMATION

[1]: comment ignored

[2]: comment ignored

[3]: comment ignored

[4]: {N_elements} {element[1]} {element[2]} ... {element[N_elements]}

[5]: {N_rho}, {d_rho}, {N_r}, {d_r}, {cutoff}

THEN FOR EACH ATOM

r is a evently spaced vector from 0 to (Nr-1)*r, in increments of dr

rho is an evenly spaced vector from 0 to (Nrho-1)*r, in increments of drho

r = np.linspace(

for i in N_elements:

[1]: atomic_number[i], mass[i], lattice_constant[i], lattice_type[i]

[2]: F(rho[1]) ... F(rho[5])  

        for N_rho values

[3]: rho(r[1]) ... rho([r[5])

        for N_r values

THEN PAIR POTENTIALS (phi(r))

for i in N_elements:

  for j in N_elements:

    if i >= j:

        phi[i][j](r)

[1]: r[1] * phi[i][j](r[1]) ... r[1] * phi[i][j](r[5])

        for N_r values

Explanation of the formatting

Creating a DYNAMO file is a somewhat difficult thing to do and it is not very well documented. This document is taken from the of C.J. O'Brien, but I've clarified some of the information provided within. I've also provided some python snippets to make the explanation more understandable. I've packaged a setfl file reader/writer in my pyflamestk python package which I am currently working on but have not published.

The EAM potential consists of three functions:

• F[i](rho) - embedding energy function which maps an electron density to an energy
• rho[i](r) - the electron density function which provides the electron density at a certain away from an atomic position
• phi[i][j](r) - a pairwise potential between element[i] and element[j]

atomic_number = atomic number

mass = atomic mass units

lattice_constant = Angstroms

lattice_type = {'FCC,BCC,HCP'}

------

[4]: pair_potential