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# mapp.dmd.atoms.ff_eam_fs¶

atoms.ff_eam_fs(fs_file, r_crd, C, elems=None)

Tabulated Finnis-Sinclair EAM

Assigns Finnis-Sinclair EAM force field to system. For explanation of the parameter see the Notes section.

Parameters: fs_file : string relative path to DYNAMO file with fs format r_crd : double[nelems] cutoff radius for mass exchange C : double[nelems] dimensionless factor for each element, see here elems : string[nelems] mapping elements None

Notes

This is tabulated form of Finnis-Sinclair Embedded Atom Method (EAM) potential

Consider the general form of EAM potential:

From here on, greek superscipts/subscripts are used to refer to elements present the system; , and denote type of atom and atom , repectively. , , and are embedding, electron density, and pair functions, respectively. Also refers to distance between and . Now the multi component formulation of DMD free energy would be:

where

The numerical evaluation of these integrals is discussed here.

Recalling that

the average potential energy is

Examples

Iron Hydrogrn mixture

>>> from mapp import dmd
>>> sim=dmd.cfg(5,"configs/FeH-DMD.cfg")
>>> sim.ff_eam_fs("potentials/FeH.eam.fs")