Molecular Potentials

4 Energy = S 2-bodies + S 3-bodies + …

4 Stillinger-Weber Si-F potential

• 2-body(r)

– A(Br^-p - r^-q) * cutoff

– cutoff = exp(C/(r-a)); r < a, 0 otherwise

• 3-body(r_ij,r_jk,j)

– (a + l (cos(j) - cos(j₀))²) * cutoff

– cutoff = exp(g/(r_ij- a₁) + g/(r_jk- a₁))

• FFF additional term

– d(r_ijr_jk)^-m * cutoff

– cutoff = exp(b/(r_ij - a₂) + b/(r_jk- a₂))