Hello, i'm Francesco Moriggi, a master student at the Milan University, i have
a problem with ph.x. I am calculating NO frequency and i'm not reaching a
convergence in values compared to cutoff energy, using norm conserving and
ultrasoft pseudopotentials. Values i get are (i've put an image too in the
email):
Cutoff freq Norm freq US
75 1879.0 1844.4
80 1875.5 1858.2
85 1890.6 1907.1
90 1923.5 1895.2
100 1889.6 1909.3
110 1914.2 1893.1
120 1890.5 1900.4
130 1890.7 1901.0
140 1914.7 1890.9
150 1886.9 ////
With Gaussian (aug-cc-pv5Z) i've got 1889.21 cm-1.
An example of the input of geometry optimization is:
&CONTROL
calculation = "relax",
prefix = "NO",
pseudo_dir = "/galileo/home/userexternal/fmoriggi/QE/NO/pseudoNO/ultrasoft",
outdir = "./out",
/
&SYSTEM
ibrav = 1,
a = 20,
nat = 2,
ntyp = 2,
nspin = 2,
ecutwfc = 150.D0,
ecutrho = 1200.D0,
occupations = 'smearing', smearing = 'gauss', degauss=0.02,
starting_magnetization(1)=-0.9,
starting_magnetization(2)=1.5,
/
&ELECTRONS
electron_maxstep = 500,
conv_thr = 1.D-7,
mixing_beta = 0.7D0,
/
&IONS
/
ATOMIC_SPECIES
O 16.00 O.pbe-van_ak.UPF
N 14.00 N.pbe-van_ak.UPF
ATOMIC_POSITIONS {angstrom}
N 1.16 0.0 0.0
O 0.000 0.0 0.0 0 0 0
K_POINTS
1
0.0 0.0 0.0 1.0
Later i've done an scf with a better conv_thr. This is the input.
&CONTROL
calculation = "scf",
prefix = "150",
pseudo_dir = "/galileo/home/userexternal/fmoriggi/QE/NO/pseudoNO/ultrasoft",
outdir = "./out150",
/
&SYSTEM
ibrav = 1,
a = 20,
nat = 2,
ntyp = 2,
nspin = 2,
ecutwfc = 150.D0,
ecutrho = 1200.D0,
occupations = 'smearing', smearing = 'gauss', degauss=0.02,
starting_magnetization(1)=-0.9,
starting_magnetization(2)=1.5,
/
&ELECTRONS
electron_maxstep = 500,
conv_thr = 1.D-9,
mixing_beta = 0.7D0,
/
&IONS
/
ATOMIC_SPECIES
O 16.00 O.pbe-van_ak.UPF
N 14.00 N.pbe-van_ak.UPF
ATOMIC_POSITIONS {angstrom}
N 1.166278 0.0 0.0
O 0.000 0.0 0.0 0 0 0
K_POINTS
1
0.0 0.0 0.0 1.0
And then i run the ph.x with this input:
phonon calculation - NO
&inputph
tr2_ph=4.0d-12,
prefix='150'
amass(1)=14.007,
amass(2)=15.9994,
outdir='/galileo/home/userexternal/fmoriggi/QE/NO/relax/ultra/out150'
/
0.0 0.0 0.0
If you can help me it would be very useful to my future TiO2 based calculations.
Best regards,
Francesco Moriggi
Webpage: http://users.unimi.it/ceotto/about_FrancescoMoriggi.html
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