diff --git a/potentials/CdTe.sw b/potentials/CdTe.sw index 94ef93e59e..f8b82d4689 100644 --- a/potentials/CdTe.sw +++ b/potentials/CdTe.sw @@ -1,34 +1,34 @@ -# Stillinger-Weber parameters for CdTe -# Parameters are from: -# -# Wang, Stroud, and Markworth, PhysRevB, 40,5, 1989 -# -# these entries are in LAMMPS "metal" units: -# epsilon = eV; sigma = Angstroms -# other quantities are unitless - -# format of a single entry (one or more lines): -# element 1, element 2, element 3, -# epsilon, sigma, a, lambda, gamma, costheta0, A, B, p, q, tol - -# Note that in LAMMPS, two-body parameters for element i and j are -# specified by the values on the i-j-j line. Two-body -# values on the i-j-i or i-i-j lines are ignored by LAMMPS, and so -# are set to zero here. - -Cd Cd Cd 1.03 2.51 1.80 25.0 1.20 -0.333333333333 - 5.1726 0.8807 4.0 0.0 0.0 -Cd Cd Te 0.0 0.0 0.0 25.0 1.20 -0.333333333333 - 0.0 0.0 0.0 0.0 0.0 -Cd Te Cd 0.0 0.0 0.0 25.0 1.20 -0.333333333333 - 0.0 0.0 0.0 0.0 0.0 -Cd Te Te 1.03 2.51 1.80 25.0 1.20 -0.333333333333 - 7.0496 0.6022 4.0 0.0 0.0 -Te Cd Cd 1.03 2.51 1.80 25.0 1.20 -0.333333333333 - 7.0496 0.6022 4.0 0.0 0.0 -Te Cd Te 0.0 0.0 0.0 25.0 1.20 -0.333333333333 - 0.0 0.0 0.0 0.0 0.0 -Te Te Cd 0.0 0.0 0.0 25.0 1.20 -0.333333333333 - 0.0 0.0 0.0 0.0 0.0 -Te Te Te 1.03 2.51 1.80 25.0 1.20 -0.333333333333 - 8.1415 0.6671 4.0 0.0 0.0 +# CdTe Stillinger-Weber potential: Z. Q. Wang, D. Stroud, +# and A. J. Markworth, Phys. Rev. B, 40, 3129(1989). + +# The Stillinger-Weber parameters given in the literature are pair +# specific. While most of the parameters are indeed pairwise parameters +# according to their definition, the parameters epsilon and lambda +# should be viewed as three-body dependent. Here we assume that the +# the three-body epsilon and lambda is a geometric mean of the pairwise +# epsilon and lambda. + +# In lammps, the parameters for the ij pair are entered in +# the ijj three-body line. There is no unique way to convert pair +# parameters to three body parameters so the example here represents +# only one way. The three-body parameters epsilon_ijk can be calculated +# from the literature pair parameters using epsilon_ijk = +# sqrt(lambda_ij*epsilon_ij*lambda_ik*epsilon_ik)/lambda_ik, and the +# results are directly entered in this table. Obviously, this +# conversion does not change the two-body parameters epsilon_ijj. +# All other ik pair parameters are entered on the i*k line, where * +# can be any species. This is consistent with the requirement of +# the ik parameter being on the ikk line. + +# These entries are in LAMMPS "metal" units: epsilon = eV; +# sigma = Angstroms; other quantities are unitless + +# epsilon sigma a lambda gamma cos(theta) A B p q tol +Cd Cd Cd 1.03 2.51 1.80 25.0 1.20 -0.333333333333 5.1726 0.8807 4.0 0.0 0.0 +Te Te Te 1.03 2.51 1.80 25.0 1.20 -0.333333333333 8.1415 0.6671 4.0 0.0 0.0 +Cd Cd Te 1.03 2.51 1.80 25.0 1.20 -0.333333333333 7.0496 0.6022 4.0 0.0 0.0 +Cd Te Te 1.03 2.51 1.80 25.0 1.20 -0.333333333333 7.0496 0.6022 4.0 0.0 0.0 +Te Cd Cd 1.03 2.51 1.80 25.0 1.20 -0.333333333333 7.0496 0.6022 4.0 0.0 0.0 +Te Cd Te 1.03 2.51 1.80 25.0 1.20 -0.333333333333 8.1415 0.6671 4.0 0.0 0.0 +Te Te Cd 1.03 2.51 1.80 25.0 1.20 -0.333333333333 7.0496 0.6022 4.0 0.0 0.0 +Cd Te Cd 1.03 2.51 1.80 25.0 1.20 -0.333333333333 5.1726 0.8807 4.0 0.0 0.0