University of Virginia, MSE 4270/6270: Introduction to Atomistic Simulations, Leonid Zhigilei
Embeddedatom and related methods for metallic systems (IV)
The development of EAMtype potentials for BCC and HCP metals is more difficult and the
progress in this direction is slower.
HCP metals:
In fitting potentials for HCP metals one should make sure that HCP structure has lower
energy as compared to FCC one and that the experimental c/a ratio, that often deviates from
the ideal value of
is reproduced.
Moreover, there are 5 independent elastic constants
to fit to in HCP as compared to 3 in cubic metals.
Examples of the reported potentials:
Oh and Johnson
developed potentials for HCP metals Mg, Ti, Zr [J. Mater. Res.
3
, 471
(1988)]
Cleri and Rosato
parameterized their potential for Ti, Zr, Co, Cd, Zn, Mg [Phys. Rev. B
48
,
22 (1993)].
Pasianot and Savino
developed a potential for Hf, Ti, Mg, Co [Phys. Rev. B
45
, 12704
(1992)].
BCC metals:
A potential for a BCC metal should predict an energetic stability of a more “open” (not close
packed) BCC structure.
BCC structure cannot be described by a pair potential.
Examples of
popular potentials for BCC metals are
FinnisSinclair
potentials for Fe, V, Nb, Ta, Mo, W
[Phil. Mag. A 50, 45 (1984)]; [Phil.
Mag. A
56
, 15 (1987)].
Oh and Johnson
developed potentials for BCC metals Li, Na, K, V, Nb, Ta, Cr, Mo, W, Fe
[J. Mater. Res.
4
, 1195 (1989)].
3
/
8
To learn about recent extensions of EAM see notes by Prof. Robert A. Johnson
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View Full DocumentUniversity of Virginia, MSE 4270/6270: Introduction to Atomistic Simulations, Leonid Zhigilei
Stillinger – Weber potential for silicon
The first term in this expression has a Lennard – Jones form, the second term is a cutoff
function that smoothly terminates the potential at a distance r
c
.
The three – body part of the
potential is given as
Stillinger  Weber potential is one of the first potentials for diamond lattices (e.g. Si, GaAs,
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 Fall '11
 Zhigilei
 Atom, Energy, Bond Order, interatomic potentials, Leonid Zhigilei

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