[Pw_forum] piezoelectricity

[hamid hasanzadeh]

hello dear all
I am working on piezoelectricity properties of materials
I runed example 10 in quantum espresso but i am not Purpose of  some
parameters in input and output files.
i look to "INPUT_PW.html" for meaninigs of this parameters but i was
not Realized to  the Real Concept of this parameters ?.please
introduce papers or books in this case.please help me.


INPUT FILE:

&control
    calculation   = 'nscf'
    pseudo_dir    = '$PSEUDO_DIR/'
    outdir        = '$TMP_DIR/'
    lberry        = .true.
PROBLEM 1.WHAT IS  THE MEANINIG OF "lberry"?
    gdir          = 2
PROBLEM 2.WHAT IS  THE MEANINIG OF "gdir "?
    nppstr        = 7
PROBLEM 3.WHAT IS THE MEANINIG OF "  nppstr "?
    ibrav         = 1
    celldm(1)     = 7.3699
    nat           = 5
    ntyp          = 3
    nbnd          = 22
    ecutwfc       = 30.0
    occupations   = 'fixed'
    degauss       = 0.00
 /
 &electrons
    conv_thr      = 1e-5
    mixing_beta   = 0.3
 /
ATOMIC_SPECIES
  Pb   207.2      Pb.pz-d-van.UPF
  Ti    47.867    Ti.pz-sp-van_ak.UPF
  O     15.9994   O.pz-van_ak.UPF
ATOMIC_POSITIONS
  Pb    0.000    0.000    0.010
  Ti    0.500    0.500    0.500
  O     0.000    0.500    0.500
  O     0.500    0.500    0.000
  O     0.500    0.000    0.500
K_POINTS {automatic}
  4 4 7  1 1 1

HAMID HASSANZADEH
M.Sc STUDENT OF FERDOWSI UNIVERCITY