diff --git a/potentials/Si.tersoff b/potentials/Si.tersoff index 85cad6c7a..b59da25d0 100644 --- a/potentials/Si.tersoff +++ b/potentials/Si.tersoff @@ -1,12 +1,16 @@ # Tersoff parameters for various elements and mixtures # multiple entries can be added to this file, LAMMPS reads the ones it needs # these entries are in LAMMPS "metal" units: # A,B = eV; lambda1,lambda2,lambda3 = 1/Angstroms; R,D = Angstroms # other quantities are unitless +# This is the Si parameterization from a particular Tersoff paper: +# J. Tersoff, PRB, 37, 6991 (1988) +# See the SiCGe.tersoff file for different Si variants. + # format of a single entry (one or more lines): # element 1, element 2, element 3, -# lambda3, c, d, costheta0, n, beta, lambda2, B, R, D, lambda1, A +# m, gamma, lambda3, c, d, costheta0, n, beta, lambda2, B, R, D, lambda1, A -Si Si Si 1.3258 4.8381 2.0417 0.0000 22.956 +Si Si Si 3.0 1.0 1.3258 4.8381 2.0417 0.0000 22.956 0.33675 1.3258 95.373 3.0 0.2 3.2394 3264.7 diff --git a/potentials/SiCGe.tersoff b/potentials/SiCGe.tersoff index 752ee9a9c..52ab9da11 100644 --- a/potentials/SiCGe.tersoff +++ b/potentials/SiCGe.tersoff @@ -1,58 +1,61 @@ # Tersoff parameters for various elements and mixtures # multiple entries can be added to this file, LAMMPS reads the ones it needs # these entries are in LAMMPS "metal" units: # A,B = eV; lambda1,lambda2,lambda3 = 1/Angstroms; R,D = Angstroms # other quantities are unitless -# Aidan Thompson takes full blame for this file. -# It specifies various potentials published by J. Tersoff for silicon, -# carbon and germanium. Since Tersoff published several different -# silicon potentials, I refer to them using atom types Si(B), -# Si(C) and Si(D). The last two are almost almost identical but refer -# to two different publications. These names should be used in the -# LAMMPS command when the file is invoked. For example: -# -# pair_coeff * * SiCGe.tersoff Si(B) -# -# The Si(D), C and Ge potentials can be used pure silicon, pure carbon, pure germanium, -# binary SiC, and binary SiGe, but not binary GeC or ternary SiGeC. LAMMPS will generate an error -# if this file is used with any combination involving C and Ge, since there are no entries for -# the GeC interactions (Tersoff did not publish parameters for this cross-interaction.) +# Aidan Thompson (athomps at sandia.gov) takes full blame for this +# file. It specifies various potentials published by J. Tersoff for +# silicon, carbon and germanium. Since Tersoff published several +# different silicon potentials, I refer to them using atom types +# Si(B), Si(C) and Si(D). The last two are almost almost identical but +# refer to two different publications. These names should be used in +# the LAMMPS command when the file is invoked. For example: +# pair_coeff * * SiCGe.tersoff Si(B). The Si(D), C and Ge potentials +# can be used pure silicon, pure carbon, pure germanium, binary SiC, +# and binary SiGe, but not binary GeC or ternary SiGeC. LAMMPS will +# generate an error if this file is used with any combination +# involving C and Ge, since there are no entries for the GeC +# interactions (Tersoff did not publish parameters for this +# cross-interaction.) # format of a single entry (one or more lines): # element 1, element 2, element 3, # m, gamma, lambda3, c, d, costheta0, n, beta, lambda2, B, R, D, lambda1, A # The original Tersoff potential for Silicon, Si(B) # J. Tersoff, PRB, 37, 6991 (1988) + Si(B) Si(B) Si(B) 3.0 1.0 1.3258 4.8381 2.0417 0.0000 22.956 0.33675 1.3258 95.373 3.0 0.2 3.2394 3264.7 # The later Tersoff potential for Silicon, Si(C) # J. Tersoff, PRB, 38, 9902 (1988) + Si(C) Si(C) Si(C) 3.0 1.0 1.7322 1.0039e5 16.218 -0.59826 0.78734 1.0999e-6 1.7322 471.18 2.85 0.15 2.4799 1830.8 # The later Tersoff potential for Carbon, Silicon, and Germanium # J. Tersoff, PRB, 39, 5566 (1989) (fixed typo in value of d for Carbon) # The Si and C parameters are very close to those in SiC.tersoff + C C C 3.0 1.0 0.0 3.8049e4 4.3484 -0.57058 0.72751 1.5724e-7 2.2119 346.7 1.95 0.15 3.4879 1393.6 Si(D) Si(D) Si(D) 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 1.7322 471.18 2.85 0.15 2.4799 1830.8 Ge Ge Ge 3.0 1.0 0.0 1.0643e5 15.652 -0.43884 0.75627 9.0166e-7 1.7047 419.23 2.95 0.15 2.4451 1769.0 C Si(D) Si(D) 3.0 1.0 0.0 3.8049e4 4.3484 -0.57058 0.72751 1.5724e-7 1.97205 395.1223 2.3573 0.1527 2.9839 1597.3111 C Si(D) C 3.0 1.0 0.0 3.8049e4 4.3484 -0.57058 0.72751 1.5724e-7 0.0 0.0 1.95 0.15 0.0 0.0 C C Si(D) 3.0 1.0 0.0 3.8049e4 4.3484 -0.57058 0.72751 1.5724e-7 0.0 0.0 2.3573 0.1527 0.0 0.0 Si(D) C C 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 1.97205 395.1223 2.3573 0.1527 2.9839 1597.3111 Si(D) Si(D) C 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 0.0 0.0 2.3573 0.1527 0.0 0.0 Si(D) C Si(D) 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 0.0 0.0 2.85 0.15 0.0 0.0 Si(D) Ge Ge 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 1.71845 444.7177 2.8996 0.1500 2.4625 1799.6347 Si(D) Si(D) Ge 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 0.0 0.0 2.8996 0.1500 0.0 0.0 Si(D) Ge Si(D) 3.0 1.0 0.0 1.0039e5 16.217 -0.59825 0.78734 1.1000e-6 0.0 0.0 2.85 0.15 0.0 0.0 Ge Si(D) Si(D) 3.0 1.0 0.0 1.0643e5 15.652 -0.43884 0.75627 9.0166e-7 1.71845 444.7177 2.8996 0.1500 2.4625 1799.6347 Ge Si(D) Ge 3.0 1.0 0.0 1.0643e5 15.652 -0.43884 0.75627 9.0166e-7 0.0 0.0 2.95 0.15 0.0 0.0 Ge Ge Si(D) 3.0 1.0 0.0 1.0643e5 15.652 -0.43884 0.75627 9.0166e-7 0.0 0.0 2.8996 0.1500 0.0 0.0