DFTK.jl

"""
DFTK --- The density-functional toolkit. Provides functionality for experimenting
with plane-wave density-functional theory algorithms.
"""
module DFTK

using Printf
using Markdown
using LinearAlgebra
using TimerOutputs
using spglib_jll
using Unitful
using UnitfulAtomic

export Vec3
export Mat3
export mpi_nprocs
export mpi_master
export setup_threading, disable_threading
include("common/timer.jl")
include("common/asserting.jl")
include("common/constants.jl")
include("common/ortho.jl")
include("common/types.jl")
include("common/spherical_harmonics.jl")
include("common/split_evenly.jl")
include("common/mpi.jl")
include("common/threading.jl")
include("common/printing.jl")

export PspHgh
include("pseudo/NormConservingPsp.jl")
include("pseudo/PspHgh.jl")

export ElementPsp
export ElementCohenBergstresser
export ElementCoulomb
export charge_nuclear
export charge_ionic
export atomic_symbol
export n_elec_valence
export n_elec_core
include("elements.jl")

export Smearing
export Model
export PlaneWaveBasis
export compute_fft_size
export G_vectors, G_vectors_cart, r_vectors, r_vectors_cart
export Gplusk_vectors, Gplusk_vectors_cart
export Kpoint
export G_to_r
export G_to_r!
export r_to_G
export r_to_G!
include("Smearing.jl")
include("Model.jl")
include("structure.jl")
include("PlaneWaveBasis.jl")
include("fft.jl")
include("orbitals.jl")
include("show.jl")

export Energies
include("Energies.jl")

export Hamiltonian
export HamiltonianBlock
export energy_hamiltonian
export Kinetic
export ExternalFromFourier
export ExternalFromReal
export AtomicLocal
export PowerNonlinearity
export LocalNonlinearity
export Hartree
export Xc
export AtomicNonlocal
export Ewald
export PspCorrection
export Entropy
export Magnetic
export Anyonic
export apply_kernel
export compute_kernel
include("terms/terms.jl")

include("occupation.jl")
export compute_density
export total_density
export spin_density
export ρ_from_total_and_spin
include("densities.jl")
include("interpolation_transfer.jl")
export compute_transfer_matrix
export transfer_blochwave
export transfer_blochwave_kpt

export PreconditionerTPA
export PreconditionerNone
export lobpcg_hyper
export diag_full
export diagonalize_all_kblocks
include("eigen/preconditioners.jl")
include("eigen/diag.jl")

export model_atomic
export model_DFT
export model_PBE
export model_LDA
include("standard_models.jl")

export KerkerMixing, KerkerDosMixing, SimpleMixing, DielectricMixing
export LdosMixing, HybridMixing, χ0Mixing
export scf_nlsolve_solver
export scf_damping_solver
export scf_anderson_solver
export scf_CROP_solver
export self_consistent_field
export direct_minimization
export newton
export load_scfres, save_scfres
include("scf/chi0models.jl")
include("scf/mixing.jl")
include("scf/scf_solvers.jl")
include("scf/self_consistent_field.jl")
include("scf/direct_minimization.jl")
include("scf/newton.jl")
include("scf/scfres.jl")
include("scf/potential_mixing.jl")

export symmetry_operations
export standardize_atoms
export bzmesh_uniform
export bzmesh_ir_wedge
export kgrid_from_minimal_spacing, kgrid_from_minimal_n_kpoints
include("symmetry.jl")
include("bzmesh.jl")

export guess_density
export random_density
export load_psp
export list_psp
include("guess_density.jl")
include("pseudo/load_psp.jl")
include("pseudo/list_psp.jl")

# export pymatgen_structure
# export ase_atoms
# export load_lattice
# export load_basis
# export load_model
# export load_density
# export load_atoms
# export load_magnetic_moments
# export run_wannier90
# include("external/abinit.jl")
# include("external/load_from_python.jl")
# include("external/load_from_file.jl")
# include("external/ase.jl")
# include("external/pymatgen.jl")
# include("external/stubs.jl")  # Function stubs for conditionally defined methods

# export compute_bands
# export high_symmetry_kpath
# export plot_bandstructure
# include("postprocess/band_structure.jl")

# export compute_forces
# export compute_forces_cart
# include("postprocess/forces.jl")
# export compute_stresses
# include("postprocess/stresses.jl")
# export compute_dos
# export compute_ldos
# export compute_nos
# export plot_dos
# include("postprocess/dos.jl")
# export compute_χ0
# export apply_χ0
# include("postprocess/chi0.jl")
# export compute_current
# include("postprocess/current.jl")

# # ForwardDiff workarounds
# include("workarounds/dummy_inplace_fft.jl")
# include("workarounds/forwarddiff_rules.jl")


# function __init__()
#     # Use "@require" to only include fft_generic.jl once IntervalArithmetic or
#     # DoubleFloats has been loaded (via a "using" or an "import").
#     # See https://github.com/JuliaPackaging/Requires.jl for details.
#     #
#     # The global variable GENERIC_FFT_LOADED makes sure that things are
#     # only included once.
#     @require IntervalArithmetic="d1acc4aa-44c8-5952-acd4-ba5d80a2a253" begin
#         include("workarounds/intervals.jl")
#         !isdefined(DFTK, :GENERIC_FFT_LOADED) && include("workarounds/fft_generic.jl")
#     end
#     @require DoubleFloats="497a8b3b-efae-58df-a0af-a86822472b78" begin
#         !isdefined(DFTK, :GENERIC_FFT_LOADED) && include("workarounds/fft_generic.jl")
#     end
#     @require Plots="91a5bcdd-55d7-5caf-9e0b-520d859cae80"    include("plotting.jl")
#     @require JLD2="033835bb-8acc-5ee8-8aae-3f567f8a3819"     include("external/jld2io.jl")
#     @require WriteVTK="64499a7a-5c06-52f2-abe2-ccb03c286192" include("external/vtkio.jl")
#     @require NCDatasets="85f8d34a-cbdd-5861-8df4-14fed0d494ab" begin
#         include("external/etsf_nanoquanta.jl")
#     end
#     @require wannier90_jll="c5400fa0-8d08-52c2-913f-1e3f656c1ce9" begin
#         include("external/wannier90.jl")
#     end
# end

# very simple example to exercise precompilation
let
    using DFTK
    a = 10.26  # Silicon lattice constant in Bohr
    lattice = a / 2 * [[0 1 1.];
                       [1 0 1.];
                       [1 1 0.]]
    Si = ElementPsp(:Si, psp=load_psp("hgh/lda/Si-q4"))
    atoms = [Si => [ones(3)/8, -ones(3)/8]]
    
    model = model_atomic(lattice, atoms)
    basis = PlaneWaveBasis(model; Ecut=5, kgrid=[1, 1, 1])
    
    scfres = self_consistent_field(basis, tol=1e-0, callback=info -> nothing)
end

end # module DFTK