[Pw_forum] complex band of Cu (fwd)
Dear PWSCF users, my advisor is interested in the following question. Any suggestions? -manoj -- Forwarded message -- Date: Thu, 03 Jul 2008 11:38:14 -0400 From: Xiaoguang Zhang <x...@ornl.gov> Reply-To: zhangx at ornl.gov To: Manoj Srivastava , pw_forum at pwscf.org Cc: zhangx at ornl.gov Subject: Re: [Pw_forum] complex band of Cu (fwd) Thanks for the reply. Even though we're experimenting with the (100) direction which does allow a 2 atom/cell tetragonal unit which yields the correct band structure, we are really interested in the (111) complex bands. Why is it necessary to use a3 to define the transport direction? Wouldn't it be simpler and conceptually clearer to define the transport direction to be the norm of the base plane? Thanks, Xiaoguang Manoj Srivastava wrote: > > -- Forwarded message -- > Date: Wed, 2 Jul 2008 08:01:19 +0200 > From: Alexander > Reply-To: PWSCF Forum > To: pw_forum at pwscf.org > Subject: Re: [Pw_forum] complex band of Cu > > Dear Manoj > The PWCOND code works only for monoclinic cells > where the a3 vector of the unit cell (defining the transport direction) is > ORTHOGONAL to both a1 and a2. You SHOULD therefore use the tetragonal unit > cell with two atoms per cell. > Regards, > Alexander > > > On Tuesday 01 July 2008 21:31, Manoj Srivastava wrote: > >>Dear PWSCF users, >> I have been trying to calculate the band structure of bulk Cu. I tried >>two different kind of unit cells, 2 atoms tetragonal and 1 atom >>rhombohedron. In case of tetragonal cell, i get the right band structure, >>but in the case of rhombohedron, d bands of Cu are not at the right place. >>I believe that these calculations should not depend on the choice of unit >>cell. I would appreiate if someone could tell me what am I doing wrong? >>Attached is the band-structure file I get for rhombohedron unit cell and >>my input file is as follows- >> >> >>ibrav=0 >>celldm(1)=6.73 >>nat= 1, >>ntyp= 1, >>ecutwfc =50.0, >>occupations= 'smearing', >>smearing='gaussian', >>degauss=0.01 >> / >> >>conv_thr = 1.0e-8 >>mixing_beta=0.7 >> / >> ATOMIC_SPECIES >> Cu 63.55 Cu.pbe-paw_kj.UPF >> ATOMIC_POSITIONS >> Cu 0.0 0.0 0.0 >>K_POINTS (automatic) >>4 4 4 0 0 0 >>CELL_PARAMETERS >>0.5 -0.5 0.0 >>0.5 0.5 0.0 >>0.5 0.0 0.5 >> >># complex bands of cu along the 001 direction K_perp=0 >>cat > cu.cond.in << EOF >> >>outdir='$TMP_DIR/' >>prefixl='cu' >>band_file ='bands.cu' >>ikind=0 >>energy0=10.d0 >>denergy=-0.04d0 >>ewind=3.d0 >>epsproj=1.d-6 >> / >>1 >>0.0 0.0 1.0 >>500 >>EOF >> >>Regards, >>Manoj Srivastava >>Graduate Student >>University of Florida >>Gainesville, USA. >> >>___ >>Pw_forum mailing list >>Pw_forum at pwscf.org >>http://www.democritos.it/mailman/listinfo/pw_forum > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
[Pw_forum] complex band of Cu
Dear Manoj The PWCOND code works only for monoclinic cells where the a3 vector of the unit cell (defining the transport direction) is ORTHOGONAL to both a1 and a2. You SHOULD therefore use the tetragonal unit cell with two atoms per cell. Regards, Alexander On Tuesday 01 July 2008 21:31, Manoj Srivastava wrote: > Dear PWSCF users, > I have been trying to calculate the band structure of bulk Cu. I tried > two different kind of unit cells, 2 atoms tetragonal and 1 atom > rhombohedron. In case of tetragonal cell, i get the right band structure, > but in the case of rhombohedron, d bands of Cu are not at the right place. > I believe that these calculations should not depend on the choice of unit > cell. I would appreiate if someone could tell me what am I doing wrong? > Attached is the band-structure file I get for rhombohedron unit cell and > my input file is as follows- > > > ibrav=0 > celldm(1)=6.73 > nat= 1, > ntyp= 1, > ecutwfc =50.0, > occupations= 'smearing', > smearing='gaussian', > degauss=0.01 > / > > conv_thr = 1.0e-8 > mixing_beta=0.7 > / > ATOMIC_SPECIES > Cu 63.55 Cu.pbe-paw_kj.UPF > ATOMIC_POSITIONS > Cu 0.0 0.0 0.0 > K_POINTS (automatic) > 4 4 4 0 0 0 > CELL_PARAMETERS > 0.5 -0.5 0.0 > 0.5 0.5 0.0 > 0.5 0.0 0.5 > > # complex bands of cu along the 001 direction K_perp=0 > cat > cu.cond.in << EOF > > outdir='$TMP_DIR/' > prefixl='cu' > band_file ='bands.cu' > ikind=0 > energy0=10.d0 > denergy=-0.04d0 > ewind=3.d0 > epsproj=1.d-6 > / > 1 > 0.0 0.0 1.0 > 500 > EOF > > Regards, > Manoj Srivastava > Graduate Student > University of Florida > Gainesville, USA. > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum
[Pw_forum] complex band of Cu
Dear PWSCF users, I have been trying to calculate the band structure of bulk Cu. I tried two different kind of unit cells, 2 atoms tetragonal and 1 atom rhombohedron. In case of tetragonal cell, i get the right band structure, but in the case of rhombohedron, d bands of Cu are not at the right place. I believe that these calculations should not depend on the choice of unit cell. I would appreiate if someone could tell me what am I doing wrong? Attached is the band-structure file I get for rhombohedron unit cell and my input file is as follows- ibrav=0 celldm(1)=6.73 nat= 1, ntyp= 1, ecutwfc =50.0, occupations= 'smearing', smearing='gaussian', degauss=0.01 / conv_thr = 1.0e-8 mixing_beta=0.7 / ATOMIC_SPECIES Cu 63.55 Cu.pbe-paw_kj.UPF ATOMIC_POSITIONS Cu 0.0 0.0 0.0 K_POINTS (automatic) 4 4 4 0 0 0 CELL_PARAMETERS 0.5 -0.5 0.0 0.5 0.5 0.0 0.5 0.0 0.5 # complex bands of cu along the 001 direction K_perp=0 cat > cu.cond.in << EOF outdir='$TMP_DIR/' prefixl='cu' band_file ='bands.cu' ikind=0 energy0=10.d0 denergy=-0.04d0 ewind=3.d0 epsproj=1.d-6 / 1 0.0 0.0 1.0 500 EOF Regards, Manoj Srivastava Graduate Student University of Florida Gainesville, USA.
