[Pw_forum] missing eigenvalue
Paolo Giannozzi
giannozz at nest.sns.it
Mon Jun 16 10:53:00 CEST 2003
Hi
> HOMO is non degenerate, the difference in energy between HOMO
. and LUMO is around 0.3 ryd.
eV, not Ry. This is however what you get if you use only Nelec/2 states
for scf, which in this particular case leads to the wrong scf charge density.
You need to add more states in the scf calculation, AND to add a broadening
to the states. If HOMO and LUMO cross during self-consistency, the charge
density has discontinuous jumps and the scf procedure may not converge.
The broadening (gaussaina or whatever) smoothes the jump and allows
self-consistency to proceed smoothly to the good ground state.
With the true scf charge density, your system has a 0.1 eV HOMO-LUMO
gap. See attached input and output (for the new version of the code)
Paolo
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&control
calculation = 'scf'
restart_mode='from_scratch',
tprnfor = .true.
pseudo_dir = '/home/giannozz/O-sesame/pseudo/',
outdir='/home/giannozz/tmp/'
/
&system
ibrav= 1, celldm(1) =24.00, nat= 6, ntyp= 1,
ecutwfc=20.0,
nbnd = 14, occupations='smearing', smearing='gaussian',
degauss=0.05
/
&electrons
mixing_mode = 'plain'
mixing_beta = 0.7
conv_thr = 1.0d-8
/
ATOMIC_SPECIES
Al 26.98 Al.vbc.UPF
ATOMIC_POSITIONS {alat}
Al 0.149002977 0.010536102 0.000000000
Al -0.149002977 -0.010536102 0.000000000
Al .010536102 0.149002977 0.000000000
Al -.010536102 -0.149002977 0.000000000
Al 0.000000000 0.000000000 0.149002977
Al 0.000000000 0.000000000 -0.149002977
K_POINTS {Gamma}
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Program PWSCF 1.2.1 starts ...
Today is 16Jun2003 at 10:42:52
Ultrasoft (Vanderbilt) Pseudopotentials, Gamma point
Current dimensions of program pwscf are:
ntypx = 6 npk =40000 lmax = 3
nchix = 6 ndim = 2000 nbrx = 8 nqfm = 8
bravais-lattice index = 1
lattice parameter (a_0) = 24.0000 a.u.
unit-cell volume = 13824.0000 (a.u.)^3
number of atoms/cell = 6
number of atomic types = 1
kinetic-energy cutoff = 20.0000 Ry
charge density cutoff = 80.0000 Ry
convergence threshold = 1.0E-08
beta = 0.7000
number of iterations used = 8 plain mixing
Exchange-correlation = SLA PZ NOGX NOGC (1100)
iswitch = 0
celldm(1)= 24.00000 celldm(2)= 0.00000 celldm(3)= 0.00000
celldm(4)= 0.00000 celldm(5)= 0.00000 celldm(6)= 0.00000
crystal axes: (cart. coord. in units of a_0)
a(1) = ( 1.0000 0.0000 0.0000 )
a(2) = ( 0.0000 1.0000 0.0000 )
a(3) = ( 0.0000 0.0000 1.0000 )
reciprocal axes: (cart. coord. in units 2 pi/a_0)
b(1) = ( 1.0000 0.0000 0.0000 )
b(2) = ( 0.0000 1.0000 0.0000 )
b(3) = ( 0.0000 0.0000 1.0000 )
PSEUDO 1 is Al zval = 3.0 lmax= 1 lloc= 0
(in numerical form: 171 grid points, xmin = 0.00, dx = 0.0000)
atomic species valence mass pseudopotential
Al 3.00 26.98000 Al( 1.00)
8 Sym.Ops. (with inversion)
Cartesian axes
site n. atom positions (a_0 units)
1 Al tau( 1) = ( 0.1490030 0.0105361 0.0000000 )
2 Al tau( 2) = ( -0.1490030 -0.0105361 0.0000000 )
3 Al tau( 3) = ( 0.0105361 0.1490030 0.0000000 )
4 Al tau( 4) = ( -0.0105361 -0.1490030 0.0000000 )
5 Al tau( 5) = ( 0.0000000 0.0000000 0.1490030 )
6 Al tau( 6) = ( 0.0000000 0.0000000 -0.1490030 )
number of k points= 1 gaussian broad. (ryd)= 0.0500 ngauss = 0
cart. coord. in units 2pi/a_0
k( 1) = ( 0.0000000 0.0000000 0.0000000), wk = 2.0000000
G cutoff = 1167.2200 ( 83519 G-vectors) FFT grid: ( 72, 72, 72)
nbndx = 56 nbnd = 14 natomwfc = 24 npwx = 10408
nelec = 18.00 nkb = 24 ngl = 975
Initial potential from superposition of free atoms
starting charge = 17.98766
Starting wfc are atomic
total cpu time spent up to now is 7.97 secs
iteration # 1 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 1.00E-02, avg # of iterations = 3.0
total energy = -24.07499764 ryd
estimated scf accuracy < 0.66195088 ryd
total cpu time spent up to now is 22.32 secs
iteration # 2 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 3.68E-03, avg # of iterations = 3.0
total energy = -23.88371294 ryd
estimated scf accuracy < 0.96342749 ryd
total cpu time spent up to now is 37.00 secs
iteration # 3 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 3.68E-03, avg # of iterations = 2.0
total energy = -24.43852687 ryd
estimated scf accuracy < 0.00104193 ryd
total cpu time spent up to now is 49.96 secs
iteration # 4 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 5.79E-06, avg # of iterations = 4.0
total energy = -24.44004936 ryd
estimated scf accuracy < 0.00014695 ryd
total cpu time spent up to now is 67.04 secs
iteration # 5 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 8.16E-07, avg # of iterations = 2.0
total energy = -24.44008319 ryd
estimated scf accuracy < 0.00001476 ryd
total cpu time spent up to now is 80.39 secs
iteration # 6 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 8.20E-08, avg # of iterations = 5.0
total energy = -24.44008813 ryd
estimated scf accuracy < 0.00000177 ryd
total cpu time spent up to now is 96.25 secs
iteration # 7 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 9.81E-09, avg # of iterations = 5.0
total energy = -24.44008868 ryd
estimated scf accuracy < 0.00000027 ryd
total cpu time spent up to now is 111.44 secs
iteration # 8 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 1.51E-09, avg # of iterations = 4.0
total energy = -24.44008880 ryd
estimated scf accuracy < 0.00000001 ryd
total cpu time spent up to now is 125.38 secs
iteration # 9 ecut= 20.00 ryd beta=0.70
Davidson diagonalization with overlap
ethr = 6.13E-11, avg # of iterations = 3.0
k = 0.0000 0.0000 0.0000 (10408 PWs) bands (ev):
-11.9006 -8.7303 -8.2956 -7.9044 -5.2864 -5.1763 -4.6844 -4.4611
-4.1198 -4.0166 -2.6876 -2.5753 -2.4730 -1.2740
the Fermi energy is -3.9438 ev
! total energy = -24.44008880 ryd
estimated scf accuracy < 0.00000000 ryd
band energy sum = -8.87823805 ryd
one-electron contribution = -60.53071604 ryd
hartree contribution = 31.30455932 ryd
xc contribution = -8.41306975 ryd
ewald contribution = 13.28117646 ryd
correction for metals = -0.08203880 ryd
convergence has been achieved
Forces acting on atoms (Ry/au):
atom 1 type 1 force = 0.00707363 -0.01749475 0.00000000
atom 2 type 1 force = -0.00707363 0.01749475 0.00000000
atom 3 type 1 force = -0.01749475 0.00707363 0.00000000
atom 4 type 1 force = 0.01749475 -0.00707363 0.00000000
atom 5 type 1 force = 0.00000000 0.00000000 -0.00257516
atom 6 type 1 force = 0.00000000 0.00000000 0.00257516
Total force = 0.103424 Total SCF correction = 0.000069
Writing file pwscf.pun for program phonon
PWSCF : 2m20.74s CPU time
init_run : 7.83s CPU
electrons : 131.11s CPU
forces : 1.63s CPU
electrons : 131.11s CPU
c_bands : 84.81s CPU ( 9 calls, 9.423 s avg)
sum_band : 15.35s CPU ( 9 calls, 1.705 s avg)
v_of_rho : 19.41s CPU ( 19 calls, 1.022 s avg)
mix_rho : 11.17s CPU ( 9 calls, 1.241 s avg)
c_bands : 84.81s CPU ( 9 calls, 9.423 s avg)
init_us_2 : 1.30s CPU ( 19 calls, 0.068 s avg)
cegterg : 83.17s CPU ( 9 calls, 9.241 s avg)
sum_band : 15.35s CPU ( 9 calls, 1.705 s avg)
wfcrot : 4.68s CPU
cegterg : 83.17s CPU ( 9 calls, 9.241 s avg)
h_psi : 77.35s CPU ( 41 calls, 1.887 s avg)
g_psi : 0.60s CPU ( 31 calls, 0.019 s avg)
overlap : 2.29s CPU ( 31 calls, 0.074 s avg)
cdiaghg : 0.33s CPU ( 32 calls, 0.010 s avg)
update : 4.39s CPU ( 31 calls, 0.142 s avg)
last : 0.88s CPU ( 9 calls, 0.098 s avg)
h_psi : 77.35s CPU ( 41 calls, 1.887 s avg)
init : 0.49s CPU ( 41 calls, 0.012 s avg)
add_vuspsi : 3.95s CPU ( 41 calls, 0.096 s avg)
General routines
cft3 : 15.46s CPU ( 76 calls, 0.203 s avg)
cft3s : 64.82s CPU ( 485 calls, 0.134 s avg)
davcio : 0.16s CPU ( 10 calls, 0.016 s avg)
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