ED_MAIN.f90

module ED_MAIN
  USE ED_INPUT_VARS
  USE ED_VARS_GLOBAL
  USE ED_EIGENSPACE, only: state_list,es_delete_espace,delete_eigenspace
  USE ED_AUX_FUNX
  USE ED_HLOC_DECOMPOSITION
  USE ED_SETUP
  USE ED_BATH
  USE ED_HAMILTONIAN
  USE ED_GREENS_FUNCTIONS
  USE ED_OBSERVABLES
  USE ED_DIAG
  USE SF_IOTOOLS, only: str,reg
  USE SF_TIMER,only: start_timer,stop_timer
  implicit none
  private



  interface ed_init_solver
     module procedure :: ed_init_solver_single
#ifdef _MPI
     module procedure :: ed_init_solver_single_mpi
#endif
  end interface ed_init_solver

  interface ed_solve
     module procedure :: ed_solve_single
#ifdef _MPI
     module procedure :: ed_solve_single_mpi
#endif
  end interface ed_solve


  public :: ed_init_solver
  public :: ed_solve




contains





  ! PURPOSE: allocate and initialize one or multiple baths -+!
  subroutine ed_init_solver_single(bath)
    real(8),dimension(:),intent(inout) :: bath
    logical                            :: check 
    logical,save                       :: isetup=.true.
    integer                            :: i
    !
    write(LOGfile,"(A)")"INIT SOLVER FOR "//trim(ed_file_suffix)
    !
    !Init ED Structure & memory
    if(isetup)call init_ed_structure()
    !
    !Init bath:
    !call set_Hloc(Hloc)
    !
    check = check_bath_dimension(bath)
    if(.not.check)stop "init_ed_solver_single error: wrong bath dimensions"
    !
    bath = 0d0
    !
    call allocate_dmft_bath()
    !if( (Nspin>1) .AND. &
    !     any(Hloc(:,:,1,Nspin,:,:).ne.0d0) )stop "ED ERROR: impHloc.mask(s,s`) /= 0. Spin-Flip terms are not allowed"
    call init_dmft_bath()
    call get_dmft_bath(bath)    !dmft_bath --> user_bath
    !
    if(isetup)call setup_global
    call deallocate_dmft_bath()
    isetup=.false.
    !
  end subroutine ed_init_solver_single

  
  
#ifdef _MPI
  subroutine ed_init_solver_single_mpi(MpiComm,bath)
    integer                            :: MpiComm
    real(8),dimension(:),intent(inout) :: bath
    logical                            :: check 
    logical,save                       :: isetup=.true.
    integer                            :: i
    !
    !
    !SET THE LOCAL MPI COMMUNICATOR :
    call ed_set_MpiComm(MpiComm)
    !
    write(LOGfile,"(A)")"INIT SOLVER FOR "//trim(ed_file_suffix)
    !
    !Init ED Structure & memory
    if(isetup)call init_ed_structure()
    !
    !Init bath:
    !call set_hloc(Hloc)
    !
    check = check_bath_dimension(bath)
    if(.not.check)stop "init_ed_solver_single error: wrong bath dimensions"
    !
    bath = 0d0
    !
    call allocate_dmft_bath()
    !if(MPIMASTER   .AND. &
    !     (Nspin>1) .AND. &
    !     any(Hloc(:,:,1,Nspin,:,:).ne.0d0) )stop "ED ERROR: impHloc.mask(s,s`) /= 0. Spin-Flip terms are not allowed"
    call init_dmft_bath()
    call get_dmft_bath(bath)    !dmft_bath --> user_bath
    if(isetup)call setup_global
    call deallocate_dmft_bath()
    isetup=.false.
    !
    call ed_del_MpiComm()
    !
  end subroutine ed_init_solver_single_mpi
#endif


  !+-----------------------------------------------------------------------------+!
  !PURPOSE: solve the impurity problems for a single or many independent
  ! lattice site using ED. 
  !+-----------------------------------------------------------------------------+!
  !+-----------------------------------------------------------------------------+!
  !                              SINGLE SITE                                      !
  !+-----------------------------------------------------------------------------+!
  subroutine ed_solve_single(bath)
    real(8),dimension(:),intent(in) :: bath
    !complex(8),optional,intent(in)  :: Hloc(Nlat,Nlat,Nspin,Nspin,Norb,Norb)
    logical                         :: check
    !
    if(MpiMaster)call save_input_file(str(ed_input_file))
    !
    !if(present(Hloc))call set_Hloc(Hloc)
    !
    check = check_bath_dimension(bath)
    if(.not.check)stop "ED_SOLVE error: wrong bath dimensions"
    !
    call allocate_dmft_bath()
    call set_dmft_bath(bath)    !user_bath --> dmft_bath
    call write_dmft_bath(LOGfile)
    if(MpiMaster)call save_dmft_bath(used=.true.)
    !
    !
    !SOLVE THE QUANTUM IMPURITY PROBLEM:
    call diagonalize_impurity()         !find target states by digonalization of Hamiltonian
    call buildgf_impurity()             !build the one-particle impurity Green's functions  & Self-energy
    ! if(chiflag)call buildchi_impurity() !build the local susceptibilities (spin [todo charge])
    call observables_impurity()         !obtain impurity observables as thermal averages.
    call get_custom_observables()       !obtain custom user-defined observables(if initialized)
    call local_energy_impurity()        !obtain the local energy of the effective impurity problem
    !
    call deallocate_dmft_bath()
    call es_delete_espace(state_list)
    !
    nullify(spHtimesV_p)
  end subroutine ed_solve_single
#ifdef _MPI
  !+-----------------------------------------------------------------------------+!
  !                              SINGLE SITE                                      !
  !+-----------------------------------------------------------------------------+!
  subroutine ed_solve_single_mpi(MpiComm,bath)
    integer                         :: MpiComm
    real(8),dimension(:),intent(in) :: bath
    !complex(8),optional,intent(in)  :: Hloc(Nlat,Nlat,Nspin,Nspin,Norb,Norb)
    logical                         :: check
    !
    !SET THE LOCAL MPI COMMUNICATOR :
    call ed_set_MpiComm(MpiComm)
    !
    if(MpiMaster)call save_input_file(str(ed_input_file))
    !
    !if(present(Hloc))call set_Hloc(Hloc)
    !
    check = check_bath_dimension(bath)
    if(.not.check)stop "ED_SOLVE error: wrong bath dimensions"
    !
    call allocate_dmft_bath()
    call set_dmft_bath(bath)    !user_bath --> dmft_bath
    call write_dmft_bath(LOGfile)
    if(MpiMaster)call save_dmft_bath(used=.true.)
    !
    !
    !SOLVE THE QUANTUM IMPURITY PROBLEM:
    call diagonalize_impurity()         !find target states by digonalization of Hamiltonian
    call buildgf_impurity()             !build the one-particle impurity Green's functions  & Self-energy
    ! if(chiflag)call buildchi_impurity() !build the local susceptibilities (spin [todo charge])    
    call observables_impurity()         !obtain impurity observables as thermal averages.
    call get_custom_observables()       !obtain custom user-defined observables(if initialized)
    call local_energy_impurity()        !obtain the local energy of the effective impurity problem
    !
    call deallocate_dmft_bath()
    call es_delete_espace(state_list)
    !
    !DELETE THE LOCAL MPI COMMUNICATOR:
    call ed_del_MpiComm()
    !
    nullify(spHtimesV_p)
  end subroutine ed_solve_single_mpi
#endif















end module ED_MAIN