# Ytterbium, one atom per primitive cell, fcc structure
# test of ddk for l=3, compute derivative of eigenenergy
# Warning : completely unphysical, as yb is treated as an insulator
# with a crazy cut-off, and only 2 k points
ndtset 3
#For most datasets
nkpt 2
kpt 3*0.25
0.25 0.5 0.5
wtk 1 3
#Dataset 1
prtden1 1
tolwfr1 1.0d-21
nstep1 30
#Dataset 2
getden2 1
iscf2 -2
nkpt2 3
nstep2 15
kpt2 0.2500 0.2500 0.2500
0.251 0.251 0.251
0.253 0.253 0.253
#Dataset 3
rfelfd3 2
rfdir3 1 0 0
getwfk3 1
getddk3 3 ! This is needed for the localisation tensor
nstep3 1
iscf3 -3
#Common data
acell 3*10.000
dielng 0.8
ecut 4.5
enunit 2
kptopt 0
natom 1
nband 10
occopt 7
tolwfr 1.0d-14
typat 1
xred 3*0.00d0
znucl 70.0
#%%
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test =
#%% t09.out, tolnlines = 0, tolabs = 0.000e+00, tolrel = 0.000e+00, fld_options = -easy
#%% psp_files = 70yb.pspnc
#%% [paral_info]
#%% max_nprocs = 2
#%% [extra_info]
#%% authors = Unknown
#%% keywords = NC, DFPT
#%% description =
#%% FCC Yb (1 atom per unit cell),
#%% using a l=3 psp with s local part.
#%% Crazy cut-off and number of k points.
#%% Shows that the derivative of the eigenenergies
#%% with respect to the wavevector can be obtained
#%% both by finite differences and analytical means
#%% (from a preliminary computation in the
#%% treatment of the ddk perturbation).
#%% For the (0.25,0.25,0.25) k point,
#%% the tenth band eigenvalue is -3.01209 eV.
#%% Going to the (0.251,0.251,0.251) k point
#%% it becomes -3.00562 eV, with finite-difference
#%% estimation of the derivative with respect
#%% to ONE wavevector change (all three
#%% components changed) being 0.00647 eV/0.001/3=2.157 eV
#%% This value is unchanged when using the
#%% data at the (0.253,0.253,0.253) k point.
#%% The analytical value is 2.15566 eV.
#%%