Open mikeatm opened 6 years ago
Yeah, It seems to be that BandUp does not work with QE spin polarized calculations. I have got an error during unfolding process.
It seems that BANDUP code is not implemented for spin polarized calculations.
Hello!
First, sorry for not replying very quickly to this. I am working on other projects now and it has been extremely difficult to maintain the code without help (this is actually why I made the code free and open from the beginning, so people in the community could not only use it, but also collaborate with coding).
Back to your question: I use QE's own routines to read QE wavefunctions (I didn't write those myself). In general, however, you select the spin channel to be parsed by bandup by using the command line option "-spin_channel", e.g., "./bandup -spin_channel 2" (you can run the code with the "-h" option to get a list of all supported command line arguments).
Does that work? If not, then I can assist anyone interested in helping fixing this.
Indeed, I run band up with the spin channel option but i got: ########################################################################################################################
########################################################################################################################
I recompiled the iotk module in QE but this error persist. I will be glad to collaborate solving this issue and extend this code to other ab-initio packages.
Replacing the subroutine "read_qe_evec_file" in the read_qe_wavefunctions_mod.f90 by the following lines would fix the issue involving the spin-polarized case. Best, Pilkwang Kim, SNU, Korea
subroutine read_qe_evc_file(wf, args, ikpt, read_coeffs, iostat)
implicit none
! Mandatory input and output variables
type(pw_wavefunction), intent(inout) :: wf
type(comm_line_args), intent(in) :: args
integer, intent(in) :: ikpt
! Optional input and output variables
logical, optional, intent(in) :: read_coeffs
integer, optional, intent(out) :: iostat
! Local variables
integer, dimension(:,:), allocatable :: G_frac
integer :: nkpts, n_pw, n_bands, n_bands_up, n_bands_down, n_spin, n_spinor, &
input_file_unit, ios, alloc_stat, i, j, ipw, i_spinor
real(kind=dp) :: e_fermi, ef_up, ef_dw, alat, encut
real(kind=dp), dimension(1:3,1:3) :: A_matrix, B_matrix
real(kind=dp), dimension(:,:), allocatable :: cart_coords_all_kpts, eigenvales, occupations
logical :: is_spinor, two_efs, read_coefficients
character(len=256) :: prefix, outdir, xml_data_file_folder, xml_data_file, &
length_units_kpts, length_units, e_units, encut_units
integer :: jkpt
if(present(iostat)) iostat = -1
read_coefficients = .TRUE.
if(present(read_coeffs)) read_coefficients = read_coeffs
input_file_unit = available_io_unit()
outdir = trim(adjustl(args%qe_outdir))
prefix = trim(adjustl(args%qe_prefix))
xml_data_file_folder = trim(outdir) // '/' // trim(prefix) // '.save'
xml_data_file = trim(xml_data_file_folder) // "/data-file.xml"
call qexml_init(input_file_unit, dir=xml_data_file_folder)
call qexml_openfile(xml_data_file, "read", ierr=ios)
if(ios/=0)then
write(*,'(3A)')'ERROR (read_qe_evc_file): Problems opening the XML data-file "', &
trim(adjustl(xml_data_file)),'"!'
return
endif
call qexml_read_bands_info(nbnd=n_bands, nbnd_up=n_bands_up, nbnd_down=n_bands_down, &
nspin=n_spin, noncolin=is_spinor, &
ef=e_fermi, two_fermi_energies=two_efs, &
ef_up=ef_up, ef_dw=ef_dw, &
energy_units=e_units, ierr=ios)
call qexml_read_bz(num_k_points=nkpts, ierr=ios)
if(n_spin==2) nkpts=nkpts*2
if(wf%i_spin==2) then
jkpt=ikpt+nkpts/2
else
jkpt=ikpt
endif
if(ios/=0)then
write(*,'(A)')'ERROR (read_qe_evc_file): Could not determine the number of kpts!'
return
endif
call qexml_read_cell(alat=alat, a_units=length_units, &
a1=A_matrix(1,:), a2=A_matrix(2,:), a3=A_matrix(3,:), &
ierr=ios)
if(ios/=0)then
write(*,'(A)')"ERROR (read_qe_evc_file): Could not read lattice info!"
return
endif
! Converting length units. BandUP works with Angstroms.
alat = to_angstrom(alat, length_units)
do j=1,3
do i=1,3
A_matrix(i,j) = to_angstrom(A_matrix(i,j), length_units)
enddo
enddo
length_units = 'Angstrom'
call get_rec_latt(latt=A_matrix, rec_latt=B_matrix)
! Getting list of Kpts in cartesian coordinates
deallocate(cart_coords_all_kpts, stat=alloc_stat)
allocate(cart_coords_all_kpts(1:3, 1:nkpts))
call qexml_read_bz(xk=cart_coords_all_kpts, k_units=length_units_kpts, ierr=ios)
if(ios/=0) then
write(*,'(A)')'ERROR (read_qe_evc_file): Could not read the list of kpts!'
return
endif
if(n_spin==2) then
do i=1,nkpts/2
cart_coords_all_kpts(:,i+nkpts/2)=cart_coords_all_kpts(:,i)
enddo
endif
cart_coords_all_kpts(:,:) = (twopi/alat) * cart_coords_all_kpts(:,:)
if(ios/=0)then
write(*,'(A)')'ERROR (read_qe_evc_file): Could not read info about bands!'
return
endif
deallocate(eigenvales, stat=alloc_stat)
deallocate(occupations, stat=alloc_stat)
allocate(eigenvales(1:n_bands, 1:nkpts), occupations(1:n_bands, 1:nkpts))
if(n_spin==2) then
call qexml_read_bands_pw(num_k_points=nkpts/2, nkstot=nkpts, lsda=(n_spin==2), nbnd=n_bands, &
lkpoint_dir=.TRUE., filename='default', &
et=eigenvales, wg=occupations , ierr=ios)
else
call qexml_read_bands_pw(num_k_points=nkpts, nkstot=nkpts, lsda=(n_spin==2), nbnd=n_bands, &
lkpoint_dir=.TRUE., filename='default', &
et=eigenvales, wg=occupations , ierr=ios)
endif
if(ios/=0)then
write(*,'(A)')'ERROR (read_qe_evc_file): Could not read eigenvalues and occupations!'
return
endif
call qexml_read_planewaves(ecutwfc=encut, cutoff_units=encut_units, ierr=ios)
if(ios/=0)then
write(*,'(A)')"ERROR (read_qe_evc_file): Could not read general info regarding wavefunctions!"
return
endif
n_spinor = 1
if(is_spinor) n_spinor = 2
if(read_coefficients)then
! Getting number of pw for current kpt
call qexml_read_gk(ik=ikpt, npwk=n_pw, ierr=ios)
if(ios/=0)then
write(*,'(A)')"ERROR (read_qe_evc_file): Could not determine the number of plane-waves for the current Kpt."
return
endif
wf%n_pw = n_pw
! Reading the G vectors for the current kpt
deallocate(G_frac, stat=alloc_stat)
allocate(G_frac(1:3,1:n_pw))
call qexml_read_gk(ik=ikpt, igk=G_frac, ierr=ios)
if(ios/=0)then
write(*,'(A)')"ERROR (read_qe_evc_file): Could not read G-vectors for the current Kpt."
return
endif
! Reading pw coeffs
deallocate(wf%pw_coeffs, stat=alloc_stat)
allocate(wf%pw_coeffs(1:n_spinor, 1:n_pw, 1:n_bands))
do i_spinor=1, n_spinor
call get_pw_coeffs_from_evc_file(ikpt, xml_data_file_folder, &
wf, ios, spinor_comp=i_spinor)
if(ios/=0)then
write(*,'(A)')"ERROR (read_qe_evc_file): Could not read the plane-wave coefficients for the current KPT."
return
endif
enddo
endif
! Done. Closing file now.
call qexml_closefile("read", ierr=ios)
if(ios/=0)then
write(*,'(A)')"WARNING (read_qe_evc_file): Error closing xml data-file."
endif
! Transferring data to the wf object
wf%is_spinor = is_spinor
wf%n_spinor = n_spinor
wf%n_spin = n_spin
wf%n_bands = n_bands
wf%n_bands_up = n_bands_up
wf%n_bands_down = n_bands_down
wf%encut = to_ev(encut, encut_units)
wf%e_fermi = to_ev(e_fermi, e_units)
wf%e_fermi_up = to_ev(ef_up, e_units)
wf%e_fermi_down = to_ev(ef_dw, e_units)
wf%two_efs = two_efs
if(.not. two_efs)then
wf%e_fermi_up = wf%e_fermi
wf%e_fermi_down = wf%e_fermi
endif
deallocate(wf%band_occupations, wf%band_energies, stat=alloc_stat)
allocate(wf%band_occupations(1:n_bands), wf%band_energies(1:n_bands))
wf%band_occupations(:) = occupations(:,jkpt)
do j=1, size(eigenvales, dim=1)
wf%band_energies(j) = to_ev(eigenvales(j,jkpt), e_units)
enddo
wf%A_matrix = A_matrix
wf%B_matrix = B_matrix
wf%Vcell = abs(triple_product(A_matrix(1,:), A_matrix(2,:), A_matrix(3,:)))
wf%kpt_cart_coords = cart_coords_all_kpts(:,jkpt)
wf%kpt_frac_coords = coords_cart_vec_in_new_basis(wf%kpt_cart_coords, new_basis=B_matrix)
if(read_coefficients)then
! To avoid allocating too much memory,
! the plane=wave coeffs are read directly into the wf
! Transferring G-vecs
deallocate(wf%G_frac, wf%G_cart, stat=alloc_stat)
allocate(wf%G_frac(1:n_pw), wf%G_cart(1:n_pw))
do ipw=1, n_pw
wf%G_frac(ipw)%coord(:) = G_frac(:,ipw)
wf%G_cart(ipw)%coord(:) = 0.0_dp
do j=1,3
wf%G_cart(ipw)%coord(:) = wf%G_cart(ipw)%coord(:) + &
real(G_frac(j,ipw), kind=dp)*B_matrix(j,:)
enddo
enddo
deallocate(G_frac, stat=alloc_stat)
endif
if(present(iostat)) iostat = 0
end subroutine read_qe_evc_file
Related to this issue: is bandup implemented for non-collinear spin case?
Dear @ahzeeshan, yes, bandup is implemented for the non-collinear spin case, when the two spin channels are mixed by spin-orbit coupling (wavefunctions are spinors) That was the snece of the paper http://dx.doi.org/10.1103/PhysRevB.91.041116 . When the spin channels are separated (spin-polarised) the unfolding procedure is the same as for scalar (spinless) wavefunctions. The only problem could be in reading wavefunctions and consistency with the particular version of the abinitio code.
Spin pilarized calculations with QE can be performed with banduppy https://github.com/band-unfolding/banduppy using the parameter spin_channel
of BandStructure
class. If needed, such option may be easily added for VASP.
Looking at your code, here and here it seems spin polarized cases are not implemented, (else this would segfault:
bandup/src/external/espresso-5.1_modules_for_BandUP/Modules/qexml.f90
line 4026
,ik_eff
would lead to an overflow, going beyond number of kpoints, meaning this was considered but not implemented), what is needed to introduce proper support for spin polarized cases?