TiAl structure optimisation

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Setup system:

using AtomsIO
using EmpiricalPotentials

system = load_system(joinpath(pkgdir(EmpiricalPotentials), "data/TiAl-1024.xyz"))

Setup calculator:

using Unitful
using UnitfulAtomic

# Note: These are completely made up parameters,
#       please do not use in production
rcut = 5.0u"Å"
zAl = atomic_number(ChemicalSpecies(:Al))
zTi = atomic_number(ChemicalSpecies(:Ti))
emins = Dict( (zAl, zAl) => -1.0u"eV",
              (zAl, zTi) => -1.234u"eV",
              (zTi, zTi) => -0.345u"eV" )
rmins = Dict( (zAl, zAl) => 2.7u"Å",
              (zAl, zTi) => 3.2u"Å",
              (zTi, zTi) => 3.0u"Å" )
calc = LennardJones(emins, rmins, rcut)

Minimise energy:

using GeometryOptimization
GO = GeometryOptimization

results = minimize_energy!(system, calc, GO.OptimCG(); maxiters=10, verbosity=1)
Geometry optimisation convergence (in atomic units)
┌─────┬─────────────────┬───────────┬────────────┬────────┐
│   n │          Energy │ log10(ΔE) │ max(Force) │  Δtime │
├─────┼─────────────────┼───────────┼────────────┼────────┤
│   0 │ +1096.106742193 │           │    93.6673 │  5.96s │
│   1 │ +736.3487865401 │      2.56 │     9.6442 │  417ms │
│   2 │ +531.3228914401 │      2.31 │    4.00447 │ 96.6ms │
│   3 │ +414.6962113208 │      2.07 │    2.11298 │  168ms │
│   4 │ +343.0263844183 │      1.86 │    2.01753 │  102ms │
│   5 │ +290.7527758817 │      1.72 │    1.61639 │  105ms │
│   6 │ +253.1970333491 │      1.57 │    1.23331 │  395ms │
│   7 │ +224.3375058040 │      1.46 │   0.999094 │ 89.5ms │
│   8 │ +202.7700356083 │      1.33 │   0.744193 │  107ms │
│   9 │ +188.2385733447 │      1.16 │   0.867713 │  110ms │
│  10 │ +178.8767383857 │      0.97 │   0.550467 │  125ms │
┌ Warning: Geometry optimisation not converged.
@ GeometryOptimization ~/work/GeometryOptimization.jl/GeometryOptimization.jl/src/optimization.jl:157

Final structure:

results.system
FlexibleSystem(Al₅₁₂Ti₅₁₂, periodicity = TTT):
    cell_vectors      : [ 21.6648        0        0;
                                0  21.6648        0;
                                0        0  31.2377]u"Å"
    energy            : -108891.754076
    config_type       : TiAl_T5000