############################################################
# GS + Band Structure + Fermi Surface calculation for MgB2
############################################################

ndtset  3

#Dataset 1 : GS calculation
kptopt1  1              # Use symmetry and treat only inequivalent points
ngkpt1   2 2 2
nshiftk1 1
shiftk1  0.0 0.0 0.5    # This choice preserves the hexagonal symmetry of the grid,
occopt1  4              # Marzari smearing
tsmear1  0.03
prtden1  1
tolvrs1  1.0d-10

#Dataset 2 : Band structure calculation.
iscf2  -2
getden2 1
kptopt2 -6
tolwfr2  1.0d-8
ndivsm2  4     # Use 4 division for the smallest segment of the path. The remaining number
               # of divisions will be automatically calculated such that the path is normalized.
kptbounds2     # Extrema of the k-path.
           0.0 0.0 0.0  #Gamma
           0.5 0.0 0.0  #M
           1/3 1/3 0.0  #K
           1/3 1/3 0.5  #H
           0.5 0.0 0.5  #L
           0.0 0.0 0.5  #A
           0.0 0.0 0.0  #Gamma

#Dataset 3 : Output of the Fermi surface
prtfsurf3 1  # To output the FS
#prtwf3   0
getwfk3 -1
iscf3   -3   # NSCF calculation, occupancies and Fermi level are calculated once convergence is achieved.
             # It should give the same FS as a GS calculation provided that the two
             # k-meshes are sufficiently dense.
getden3 1
occopt3 4
tsmear3 0.03
kptopt3 1
ngkpt3   8 8 8       # too coarse. 24 24 24 for a reasonable FS
shiftk3  0.0 0.0 0.0 # Shifted grids are not supported by Xcrysden.
tolwfr3  1.0d-8

#COMMON INPUT DATA###########################################################
#
ecut    10.0  #Definition of the plane wave basis set
nband   11
nstep   50

# MgB2 lattice structure
ntypat   2
znucl   12 5
natom   3
typat   1*1 2*2

acell   2*3.086  3.523 Angstrom

rprim   0.866025403784439  0.5  0.0
       -0.866025403784439  0.5  0.0
        0.0                0.0  1.0

# Atomic positions
xred
 0.0000000000E+00  0.0000000000E+00  0.0 #Mg
 1/3               2/3               0.5 #B
 2/3               1/3               0.5 #B

 pp_dirpath "$ABI_PSPDIR"
 pseudos "PseudosTM_pwteter/12mg.pspnc, 05b.soft_tm"

#%%<BEGIN TEST_INFO>
#%% [setup]
#%% executable = abinit
#%% [files]
#%% files_to_test = 
#%%   t14.out, tolnlines = 2, tolabs = 1.1e-5, tolrel = 2.0e-4, fld_options = -medium
#%% [paral_info]
#%% max_nprocs = 2
#%% [extra_info]
#%% authors = M. Giantomassi
#%% keywords = 
#%% description = 
#%%   MgB2, space group P6/m m m (#191); Bravais hP (primitive hexag.)
#%%   GS calculation followed by a band structure calculation in which the
#%%   k-path is automatically defined via the ndivsm input variable.
#%%   The third dataset tests the calculation and the output of the Fermi surface (prtfsurf=1)
#%%   in the Xcrysden format. 
#%% topics = ElecBandStructure
#%%<END TEST_INFO>