TABLE OF CONTENTS

ABINIT/fermi_green [ Functions ]

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NAME

 fermi_green

FUNCTION

  Compute Fermi level for DMFT or LDA.

COPYRIGHT

 Copyright (C) 2006-2018 ABINIT group (BAmadon)
 This file is distributed under the terms of the
 GNU General Public License, see ~abinit/COPYING
 or http://www.gnu.org/copyleft/gpl.txt .

INPUTS

 fermie: current value
 f_precision: precision of f required
 ITRLST: =1 if last iteration of DMFT
 opt_noninter   : if one wants the LDA fermi level
 max_iter : max number of iterations.

OUTPUT

 fermie: output value

CHILDREN

  wrtout, spline_c,invfourier, nfourier

PARENTS

      dmft_solve

CHILDREN

      compute_green,integrate_green,newton,wrtout

SOURCE

 36 #if defined HAVE_CONFIG_H
 37 #include "config.h"
 38 #endif
 39 
 40 
 41 #include "abi_common.h"
 42 
 43 subroutine fermi_green(cryst_struc,green,paw_dmft,pawang,&
 44 & self)
 45 
 46  use m_profiling_abi
 47 
 48  use defs_basis
 49  use defs_abitypes
 50  use m_pawang, only : pawang_type
 51  use m_crystal, only : crystal_t
 52  use m_green, only : green_type,integrate_green,compute_green
 53  use m_paw_dmft, only: paw_dmft_type
 54  use m_self, only : self_type
 55 
 56 !This section has been created automatically by the script Abilint (TD).
 57 !Do not modify the following lines by hand.
 58 #undef ABI_FUNC
 59 #define ABI_FUNC 'fermi_green'
 60  use interfaces_14_hidewrite
 61  use interfaces_68_dmft, except_this_one => fermi_green
 62 !End of the abilint section
 63 
 64  implicit none
 65 
 66 !Arguments ------------------------------------
 67 !scalars
 68  type(crystal_t),intent(in) :: cryst_struc
 69  type(green_type),intent(inout) :: green
 70  type(paw_dmft_type), intent(inout) :: paw_dmft
 71  !type(MPI_type), intent(in) :: mpi_enreg
 72  type(pawang_type),intent(in) :: pawang
 73  type(self_type), intent(inout) :: self
 74 
 75 !Local variables-------------------------------
 76  integer :: ierr_hh,opt_noninter,max_iter
 77  real(dp):: x_precision,f_precision,fermi_old
 78 ! real(dp) :: hx 
 79  character(len=500) :: message
 80 !************************************************************************
 81 !
 82  write(message,'(a,8x,a)') ch10,"  == Compute Fermi level"
 83  call wrtout(std_out,message,'COLL')
 84 
 85 !=============
 86 !headers
 87 !=============
 88  write(message,'(2a)') ch10, "  |---Newton method to search Fermi level ------------|"
 89  call wrtout(std_out,message,'COLL')
 90  write(message,'(2a,f13.6)') ch10, "  |--- Initial value for Fermi level",paw_dmft%fermie
 91  call wrtout(std_out,message,'COLL')
 92 
 93 !========================================
 94 !Define precision and nb of iterations
 95 !=========================================
 96  fermi_old=paw_dmft%fermie
 97  ierr_hh=0
 98  f_precision=paw_dmft%dmft_chpr
 99  !f_precision=0.01
100  x_precision=tol5
101 !if(option==1) then
102 !f_precision=(erreursurlacharge)/100d0
103 !else
104 !f_precision=tol11
105 !endif
106  max_iter=1 ! for tests only
107  !write(6,*) "for tests max_iter=1"
108  max_iter=50
109  opt_noninter=4
110 
111 !=====================
112 !Call newton method
113 !=====================
114  write(message,'(a,4x,a,e13.6)') ch10," Precision required :",f_precision
115  call wrtout(std_out,message,'COLL')
116  if (f_precision<10_dp)  then
117    call newton(cryst_struc,green,paw_dmft,pawang,self,&
118 &   paw_dmft%fermie,x_precision,max_iter,f_precision,ierr_hh,opt_noninter)
119  end if
120 
121 !===========================
122 !Deals with errors signals
123 !===========================
124  if(ierr_hh==-314) then
125    write(message,'(a)') "Warning, check Fermi level"
126    call wrtout(std_out,message,'COLL')
127 !  call leave_new('COLL')
128    write(message,'(2a,f13.6)') ch10, "  |---  Final  value for Fermi level (check)",paw_dmft%fermie
129    call wrtout(std_out,message,'COLL')
130  else if (ierr_hh==-123) then
131    write(message,'(a,f13.6)') " Fermi level is put to",fermi_old
132    paw_dmft%fermie=fermi_old
133    call wrtout(std_out,message,'COLL')
134 
135 !  =====================================
136 !  If fermi level search was successful
137 !  =====================================
138  else
139    write(message,'(a,4x,a,e13.6)') ch10," Precision achieved on Fermi Level :",x_precision
140    call wrtout(std_out,message,'COLL')
141    write(message,'(4x,a,e13.6)') " Precision achieved on number of electrons :",f_precision
142    call wrtout(std_out,message,'COLL')
143    write(message,'(2a,f13.6)') ch10, "  |---  Final  value for Fermi level",paw_dmft%fermie
144    call wrtout(std_out,message,'COLL')
145  end if
146 
147 !========================================================
148 !Check convergence of fermi level during DMFT iterations
149 !========================================================
150  if(paw_dmft%idmftloop>=2) then
151    if(abs(paw_dmft%fermie-fermi_old).le.paw_dmft%dmft_fepr) then
152 !    write(message,'(a,8x,a,e9.2,a,8x,a,e12.5)') ch10,"|fermie(n)-fermie(n-1)|=<",paw_dmft%dmft_fepr,ch10,&
153      write(message,'(a,8x,a,e9.2,a,e9.2,a,8x,a,e12.5)') ch10,"|fermie(n)-fermie(n-1)|=",&
154 &     abs(paw_dmft%fermie-fermi_old),"<",paw_dmft%dmft_fepr,ch10,&
155 &     "=> DMFT Loop: Fermi level is converged to:",paw_dmft%fermie
156      call wrtout(std_out,message,'COLL')
157      green%ifermie_cv=1
158    else
159      write(message,'(a,8x,a,2f12.5)') ch10,"DMFT Loop: Fermi level is not converged:",&
160 &     paw_dmft%fermie
161      call wrtout(std_out,message,'COLL')
162      green%ifermie_cv=0
163    end if
164  end if
165  write(message,'(2a)') ch10, "  |---------------------------------------------------|"
166  call wrtout(std_out,message,'COLL')
167 !
168 
169 !==========================================================
170 !Recompute full green function including non diag elements
171 !==========================================================
172  call compute_green(cryst_struc,green,paw_dmft,pawang,0,self,opt_self=1,opt_nonxsum=1)
173  call integrate_green(cryst_struc,green,paw_dmft,pawang,prtopt=0,opt_ksloc=3) !,opt_nonxsum=1)
174 
175  return 
176 end subroutine fermi_green