1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
# NOTE: This script can be modified for different atomic structures,
# units, etc. See in.elastic for more info.
#
# Define the finite deformation size. Try several values of this
# variable to verify that results do not depend on it.
variable up equal 1.0e-6
# Define the amount of random jiggle for atoms
# This prevents atoms from staying on saddle points
variable atomjiggle equal 1.0e-5
# Uncomment one of these blocks, depending on what units
# you are using in LAMMPS and for output
# metal units, elastic constants in eV/A^3
#units metal
#variable cfac equal 6.2414e-7
#variable cunits string eV/A^3
# metal units, elastic constants in GPa
units metal
variable cfac equal 1.0e-4
variable cunits string GPa
# real units, elastic constants in GPa
#units real
#variable cfac equal 1.01325e-4
#variable cunits string GPa
# Define minimization parameters
variable etol equal 0.0
variable ftol equal 1.0e-10
variable maxiter equal 100
variable maxeval equal 1000
variable dmax equal 1.0e-2
# generate the box and atom positions using a diamond lattice
variable a equal 5.43
boundary p p p
lattice diamond $a
region box prism 0 2.0 0 3.0 0 4.0 0.0 0.0 0.0
create_box 1 box
create_atoms 1 box
# Need to set mass to something, just to satisfy LAMMPS
mass 1 1.0e-20
|
