TABLE OF CONTENTS

ABINIT/m_spectra [ Modules ]

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NAME

 m_spectra

FUNCTION

 This module contains the definition of the specta_type data type
 used to store results related to optical spectra with or without
 nonlocal field effects as well as the electron energy loss function
 for a given q. These quantities are obtained from the dielectric
 matrix as calculated in the GW part of ABINIT (screening.F90)

COPYRIGHT

 Copyright (C) 2008-2024 ABINIT group (MG)
 This file is distributed under the terms of the
 GNU General Public License, see ~abinit/COPYING
 or http://www.gnu.org/copyleft/gpl.txt .

SOURCE

20 #if defined HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23 
24 #include "abi_common.h"
25 
26 MODULE m_spectra
27 
28  use defs_basis
29  use m_errors
30  use m_abicore
31 
32  use m_io_tools,      only : open_file
33  use m_fstrings,      only : strcat
34 
35  implicit none
36 
37  private

m_spectra/dump_Qlist [ Functions ]

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NAME

  dump_Qlist

FUNCTION

  Helper function used to write the list of q-points used for the long-wavelength limit.

INPUTS

  Spectra=The Object containing the spectra

OUTPUT

  Only writing.

SOURCE

272  subroutine dump_Qlist()
273 
274   integer :: iqpt
275   write(unt,'(a,i3)')'# Q-point list, No. ',Spectra%nqpts
276   do iqpt=1,Spectra%nqpts
277     write(unt,'(a,i3,a,3f9.6,a)')'# ',iqpt,')  [',Spectra%qpts(:,iqpt),'] r.l.u. '
278   end do
279  end subroutine dump_Qlist
280 
281 end subroutine spectra_write

m_spectra/spectra_free [ Functions ]

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NAME

  spectra_free

FUNCTION

  Deallocate all associated pointers defined in the structure.

INPUTS

OUTPUT

SOURCE

157 subroutine spectra_free(Spectra)
158 
159 !Arguments ------------------------------------
160  class(spectra_t),intent(inout) :: spectra
161 
162 ! *********************************************************************
163 
164  ABI_SFREE(Spectra%omega)
165  ABI_SFREE(Spectra%qpts)
166  ABI_SFREE(Spectra%emacro_lf)
167  ABI_SFREE(Spectra%emacro_nlf)
168  ABI_SFREE(Spectra%eelf)
169 
170 end subroutine spectra_free

m_spectra/spectra_init [ Functions ]

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NAME

  spectra_init

FUNCTION

  Initialize the object.

INPUTS

OUTPUT

SOURCE

115 subroutine spectra_init(Spectra,nomega,omega,nqpts,qpts)
116 
117 !Arguments ------------------------------------
118 !scalars
119  integer,intent(in) :: nomega,nqpts
120 !arrays
121  real(dp),intent(in) :: omega(nomega),qpts(3,nqpts)
122  type(spectra_t),intent(out) :: Spectra
123 
124 ! *********************************************************************
125 
126  Spectra%nomega = nomega
127  Spectra%nqpts  = nqpts
128 
129  ABI_MALLOC(Spectra%qpts,(3,nqpts))
130  Spectra%qpts = qpts
131 
132  ABI_MALLOC(Spectra%omega,(nomega))
133  Spectra%omega = omega
134 
135  ABI_CALLOC(Spectra%emacro_lf,(nomega,nqpts))
136  ABI_CALLOC(Spectra%emacro_nlf,(nomega,nqpts))
137  ABI_CALLOC(Spectra%eelf,(nomega,nqpts))
138 
139 end subroutine spectra_init

m_spectra/spectra_repr [ Functions ]

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NAME

  spectra_repr

FUNCTION

  Returns a string reporting info on the calculated dielectric constant.

INPUTS

  Spectra=The Object containing the spectra

OUTPUT

SOURCE

300 subroutine spectra_repr(Spectra,str)
301 
302 !Arguments ------------------------------------
303 !scalars
304  class(spectra_t),intent(in) :: Spectra
305  character(len=*),intent(out) :: str
306 
307 !Local variables-------------------------------
308 !scalars
309  integer :: iqpt
310  real(dp) :: epsilon0,epsilon0_nlf
311  character(len=15), parameter :: format_f84   = '(1x,a,  f8.4,a)'
312  character(len=15), parameter :: format_es135 = '(1x,a,es13.5,a)'
313  character(len=15) :: format_diel
314  character(len=500) :: msg
315 
316 ! *********************************************************************
317 
318  !istatic = -1
319  !do io = Spectra%nomega
320  ! if (ABS(REAL(Spectra%omega(io)))<1.e-3.and.ABS(AIMAG(Spectra%omega(io)))<1.e-3) then
321  !  istatic = io
322  !  EXIT
323  ! end if
324  !end do
325 
326  str = ""
327  do iqpt=1,Spectra%nqpts
328    epsilon0    = REAL(Spectra%emacro_lf (1,iqpt))
329    epsilon0_nlf= REAL(Spectra%emacro_nlf(1,iqpt))
330    write(msg,'(a,3f9.6,a)')' For q-point: ',Spectra%qpts(:,iqpt),ch10
331    format_diel=format_f84
332    if(abs(epsilon0)>1000.0d0 .or. abs(epsilon0_nlf)>1000.0d0) format_diel=format_es135
333    str = strcat(str,msg)
334    write(msg,format_diel)' dielectric constant = ',epsilon0,ch10
335    str = strcat(str,msg)
336    write(msg,format_diel)' dielectric constant without local fields = ',epsilon0_nlf,ch10
337    str = strcat(str,msg)
338  end do
339 
340 end subroutine spectra_repr
341 
342 !----------------------------------------------------------------------
343 
344 END MODULE m_spectra

m_spectra/spectra_t [ Types ]

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NAME

 spectra_t

FUNCTION

  Object used to store optical spectra with or without non-local field effects.

SOURCE

49  type,public :: spectra_t
50 
51  !scalars
52   integer :: nomega
53   ! number of frequencies
54 
55   integer :: nqpts
56   ! number of q-points
57 
58  !arrays
59   real(dp),allocatable :: omega(:)
60   ! omega(nomega)
61   ! Real frequency mesh for optical spectra.
62 
63   real(dp),allocatable :: qpts(:,:)
64   ! qpts(3,nqpoints)
65   ! The list of q-points used for the spectra
66 
67   real(dp),allocatable :: eelf(:,:)
68   ! eelf(nomega,nqpoints)
69   ! contains the Electron Energy Loss Function i.e. -\Im{ e^{-1}_{G1=0,G2=0}(q-->0,nomega)}
70 
71   complex(dpc),allocatable :: emacro_lf(:,:)
72   ! emacro_lf(nomega,nqpoints)
73   ! contains 1/e^{-1}_{G1=0,G2=0}(q-->0,nomega) (with Local field effects)
74 
75   complex(dpc),allocatable :: emacro_nlf(:,:)
76   ! emacro_nlf(nomega,nqpoints)
77   ! contains e_{G1=0,G2=0}(q-->0,nomega) (without Local field effects)
78 
79  contains
80 
81    procedure :: free => spectra_free
82    ! Free memory.
83 
84    procedure :: write => spectra_write
85    ! Write results on file.
86 
87    procedure :: repr => spectra_repr
88    ! Return info on Macroscopic diel. constant in form of a string.
89 
90  end type spectra_t

m_spectra/spectra_write [ Functions ]

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NAME

  spectra_write

FUNCTION

  Write the optical spectra stored in the object on an external formatted file.

INPUTS

  Spectra=The Object containing the spectra
  write_bits=Positive integer defining the quantities to be written (bit representation is used)
  fname=Name of the file to be written.

OUTPUT

SOURCE

191 subroutine spectra_write(Spectra,write_bits,fname)
192 
193 !Arguments ------------------------------------
194 !scalars
195  class(spectra_t),intent(in) :: Spectra
196  integer,intent(in) :: write_bits
197  character(len=*),intent(in) :: fname
198 
199 !Local variables-------------------------------
200 !scalars
201  integer :: unt,io,iqpt
202  real(dp) :: mino,maxo
203  character(len=100) :: fmt
204  character(len=500) :: msg
205 
206 ! *********************************************************************
207 
208  if (write_bits<0) RETURN
209 
210  mino = MINVAL(Spectra%omega)
211  maxo = MAXVAL(Spectra%omega)
212 
213  if (open_file(fname,msg,newunit=unt) /= 0) then
214    ABI_ERROR(msg)
215  end if
216 
217  !write(unt,'(a,i5,2(a,f9.1),a)')'# nomega : ',Spectra%nomega,' from ',mino*Ha_eV,' up to ',maxo*Ha_eV,' [eV] '
218 
219  if ( IAND(write_bits,W_EM_NLF ) == W_EM_NLF ) then
220    write(unt,'(a)')'#'
221    write(unt,'(a)')'# Macroscopic Dielectric Function without local fields'
222    call dump_qlist()
223    write(unt,'(a)')'# Omega [eV]    Re epsilon_M       IM eps_M '
224    write(fmt,'(a,i3,a)') '(1x,f7.3,7x,',Spectra%nqpts,'(2(e12.4),2x))'
225    do io=1,Spectra%nomega
226      write(unt,fmt) Spectra%omega(io)*Ha_eV, ( Spectra%emacro_nlf(io,iqpt), iqpt=1,Spectra%nqpts )
227    end do
228  end if
229  !
230  if ( IAND(write_bits, W_EM_LF ) == W_EM_LF ) then
231    write(unt,'(a)')'#'
232    write(unt,'(a)')'# Macroscopic Dielectric Function with local fields included'
233    call dump_qlist()
234    write(unt,'(a)')'# Omega [eV]    Re epsilon_M       Im eps_M '
235    write(fmt,'(a,i3,a)') '(1x,f7.3,7x,',Spectra%nqpts,'(2(e12.4),2x))'
236    do io=1,Spectra%nomega
237      write(unt,fmt) Spectra%omega(io)*Ha_eV, ( Spectra%emacro_lf(io,iqpt), iqpt=1,Spectra%nqpts )
238    end do
239  end if
240  !
241  if ( IAND(write_bits,W_EELF) == W_EELF) then
242    write(unt,'(a)')'#'
243    write(unt,'(a)')'# Electron Energy Loss Function -Im(1/epsilon_M)'
244    call dump_qlist()
245    write(unt,'(a)')'# Omega [eV]    -Im(1/epsilon_M)'
246    write(fmt,'(a,i3,a)') '(1x,f7.3,7x,',Spectra%nqpts,'(e12.4,2x))'
247    do io=1,Spectra%nomega
248      write(unt,fmt) Spectra%omega(io)*Ha_eV, ( Spectra%eelf(io,iqpt), iqpt=1,Spectra%nqpts ) ! -AIMAG(chi0(1,1,io))
249    end do
250  end if
251 
252  close(unt)
253 
254 CONTAINS