两体势 Lennard-Jones Morse M.J.Weins, Surf. Sci. 31, 138(1972) L.A. Girifalco and G.V. Weizer, Phys. Rev, 114, 687(1959) ∑4(z)2-() ∑le -2P0(-1) P0(-1) 1< 冲击势 吸引势两体势 Lennard-Jones Morse M.J.Weins,Surf. Sci. 31, 138(1972) L.A.Girifalco and G.V.Weizer, Phys.Rev, 114,687(1959) 4 [( ) ( ) ] 12 6 ij ij r r i j V σ σ = ∑ ε − < [ 2 ] 2 ( 1) ( 1) 0 0 0 0 − − < − − = ∑ − rij r rij r V e e i j ρ ρ ε 冲击势 吸引势