[QE-users] non unifrom kpt grid at epsilon.x

[Andrea Ferretti]

Dear Vivek,

> When I run epsilon.x, I received the following error message such as 
> 'non unifrom kpt grid'. And I added nosym = .TRUE. and noinv = .TRUE. in
> to my epsilon.x input file by reading other related threads but I got 
> an another error message such as 'reading namelist ENERGY_GRID'.

note that

nosym=.true.
noinv=.true.

need to be added to the nscf input of pw.x.

the namelists of epsilon.x contain the following variables:

   NAMELIST / inputpp / prefix, outdir, calculation
   NAMELIST / energy_grid / smeartype, intersmear, intrasmear, nw, wmax, wmin, &
                            nbndmin, nbndmax, shift
   !
(as from qe/PP/src/epsilon.f90 )

the error you get ('reading namelist ENERGY_GRID') just means that you are 
specifying unexpected variable names.

> How can I solve this problem to find an absorption spectrum of my 
> system? I have tried a lot to rectify this error by reading all the 
> related threads from QE but I couldn't solve. I would be very grateful 
> if you help me out in this regard. My input file is attached below.
> 
> Thanks in advance.
> 
> # scf cal:
> 
> &control
> calculation = 'scf'
> restart_mode = 'from_scratch'
> prefix = 'TiLaO2'
> !tstress = .true.
> !tprnfor = .true.
> pseudo_dir = './'
> outdir = './outTiLaO2'
> !wf_collect=.true.
> !forc_conv_thr = 1d-5
> !etot_conv_thr = 1D-6
> /
> &system
> ibrav = 0
> celldm(1) = 14.1
> nat = 24
> ntyp = 3
> ecutwfc = 45.0
> ecutrho = 600.0
> occupations='smearing',
> smearing='gaussian',
> degauss=0.02
> nosym = .true.
> nbnd = 250
> !input_dft = 'pbe0'
> /
> &electrons
> !mixing_beta = 0.2,
> !conv_thr = 1.0d-10,
> !electron_maxstep = 200,
> !diagonalization='cg'
> /
> &IONS
> !ion_dynamics = 'bfgs'
> /
> &cell
> !cell_factor = 3
> /
> ATOMIC_SPECIES
>  Ti 47.867    Ti.UPF
>  La 138.9055  La.UPF
>  O  16.00     O.UPF
> CELL_PARAMETERS (alat)
>    0.970433204   0.000000000   0.000000000
>    0.000000000   0.485978167   0.000000000
>    0.000000000   0.000000000   1.175525500
> ATOMIC_POSITIONS (crystal)
> Ti       0.009094487   0.000000000   0.002015229
> Ti       0.490905513   0.000000000   0.002015229
> Ti       0.250000000   0.500000000   0.490725356
> La       0.750000032   0.500000000   0.508800424
> Ti       0.000769873   0.500000000   0.229350411
> Ti       0.499230127   0.500000000   0.229350411
> Ti       0.250000000   0.000000000   0.742953212
> Ti       0.750000032   0.000000000   0.795621939
> O        0.008611878   0.000000000   0.218707131
> O        0.491388122   0.000000000   0.218707131
> O        0.250000000   0.500000000   0.711522210
> O        0.750000032   0.500000000   0.791402124
> O        0.019968127   0.500000000   0.437935831
> O        0.480031873   0.500000000   0.437935831
> O        0.250000000   0.000000000   0.965224113
> O        0.750000032   0.000000000   1.010110028
> O        0.250000000   0.000000000   0.526310836
> O        0.750000032   0.000000000   0.594454704
> O        0.012728211   0.500000000   0.011818103
> O        0.487271789   0.500000000   0.011818103
> O        0.250000000   0.500000000   0.253384075
> O        0.750000032   0.500000000   0.243781210
> O        0.003322358   0.000000000   0.783028197
> O        0.496677642   0.000000000   0.783028197
> K_POINTS automatic
> 3 3 3 1 1 1
> 
> # epsilon.x:
> 
> &INPUTPP
> calculation = 'eps'
> prefix = 'TiLaO2'
> outdir = './outTiLaO2'
> /
> &energy_grid
> smeartype='gauss',
> intersmear=0.1,
> !intrasmear=0.0d0,
> wmax=30.0,
> wmin=0.0,
> nw=1000,
> !shift=0.0d0,
> nosym = .TRUE.
> noinv = .TRUE.
> /
> 
> 
> 
> Kind Regards,
> 
> Vivek C
> 
> 
> __________________________________
> 
> Vivek Christhunathan
> 
> PhD researcher
> 
> Mechanical Engineering
> 
> College of Engineering and Informatics
> 
> Room 2053
> 
> Alice Perry Engineering Building
> 
> National University of Ireland Galway
> 
> Ireland
> 
> E-mail: v.christhunathan1 at nuigalway.ie
> Phone: +353 899811181, +91 9600752742
> [uc?export=download&id=1oPtxd7PT5ljQRnuP-Gdf5upjiKPXk7Fz&revid=0B_S3ZLbRRu26NW1YallITFk1ZHMxaStQaUVoMjZ4M2NqcC9BPQ]
> 
>

-- 
Andrea Ferretti, PhD
S3 Center, Istituto Nanoscienze, CNR
via Campi 213/A, 41125, Modena, Italy
Tel: +39 059 2055322;  Skype: andrea_ferretti
URL: http://www.nano.cnr.it