[Pw_forum] strange output of matdyn.x

REI.BOND yuzuman19 at livedoor.com
Wed Jul 3 17:33:41 CEST 2013


Dear all,

I have a question of matdyn.x .
(This mail had sent once. Then no reply... )

I have calculated phonon dispersion of the materials of a one-dimensional
system(Silicon nano wire).
Then, the problem occurred.
First, I estimated the frequency of Γ point using dynmat.x.(result is
following)
As for the result, frequencies also including rotation mode was set to 0.

Next, phonon dispersion of Γ point to X point was calculated using matdyn.x
(same structure). Much negative frequencies appeared.

Especially an amusing point is that negative frequency appeared of gamma
point...
Is it strange!?!?!?!
Negative frequency at gamma point did not appear in dynmat.x .
But,negative frequency at gamma point appeared in matdyn.x .

Please help me....
MY input is so bad??????
(see attach file)

Best

Department of Applied Physics,
Graduate School of Engineering/Faculty of Engineering,
The University of Tokyo

Building No. 6, Faculty of Engineerng, Hongo Campus
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656
TEL: +81-3-5841-6800 FAX: +81-3-5841-6803

AOSHIMA

SCF inout
---------------------
 &control
    calculation='scf'
    restart_mode='restart',
    prefix='100',
    pseudo_dir = './',
    outdir='./'
    tprnfor = .true.
    tstress = .true.
 /
 &system
    ibrav=8,
    celldm(1) = 9.633168021 ,
    celldm(2) =3.480290431 ,
    celldm(3) =3.480290431 ,
!    celldm(3) = 3.472149983 ,
    nat=  21,
    ntyp= 2,
    ecutwfc =80.0,
 /
 &electrons
    diagonalization = 'cg'
    conv_thr =  1.0d-12
    mixing_beta = 0.2
    electron_maxstep = 10000
 /
ATOMIC_SPECIES
   Si 28.086     Si.pz-vbc.UPF
   H 1.00782503207 H.pz-vbc.UPF
ATOMIC_POSITIONS bohr
Si       2.382735185   4.187856452   4.187856452
Si       4.789323342   1.598574217   6.780983321
Si       7.195931863   4.187882682   9.374067631
Si       4.789323342   6.780983321   1.598574217
Si       7.195931863   9.374067631   4.187882682
Si      -0.027228530   6.780971674   6.780971674
Si       2.382730459   9.374088640   9.374088640
Si       4.789318991  11.963373368   6.780966038
Si       4.789318991   6.780966038  11.963373368
H        0.571305371   2.642525984   2.642525984
H        3.058730990  -0.053715198   8.291361254
H        6.519883004  -0.053820395   5.270682330
H        9.007309318   2.642524144  10.919428308
H        3.058730990   8.291361254  -0.053715198
H        6.519883004   5.270682330  -0.053820395
H        9.007309318  10.919428308   2.642524144
H        0.571286047  10.919410757  10.919410757
H        6.519874014  13.615773142   8.291266823
H        3.058723946  13.615653717   5.270582379
H        6.519874014   8.291266823  13.615773142
H        3.058723946   5.270582379  13.615653717
K_POINTS AUTOMATIC
16 1 1 0 0 0


SCF output
---------------------
     Total force =     0.000172     Total SCF correction =     0.000000

     entering subroutine stress ...

          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.20
   0.00000002   0.00000000   0.00000000          0.00      0.00      0.00
   0.00000000  -0.00000209   0.00000000          0.00     -0.31      0.00
   0.00000000   0.00000000  -0.00000209          0.00      0.00     -0.31

PH.x input
-------------------
phonons of sinw100
 &inputph
  tr2_ph=1.0d-14,
  prefix='100',
  ldisp=.true.,
  nq1=8, nq2=1, nq3=1
  amass(1)=28.08,
  amass(2)=1.00782503207,
  epsil = .true.,
  outdir='./',
  fildyn='100.dyn',
 /

dynmat input
-------------------
&input fildyn='100.dyn1', asr='one-dim' , axis=1 /

q2r input
------------------
 &input
   fildyn='100.dyn', zasr='one-dim', flfrc='100-811.fc'
 /

matdyn input
-------------------
&input
    asr='one-dim',  amass(1)=28.08,amass(2)=1.0078
    flfrc='100-411.fc' , flfrq='100.freq811', q_in_band_form=.true.
/
1
0.0 0.0 0.0 1

dynmat output
-------------------
     omega( 1) =      -0.000001 [THz] =      -0.000036 [cm-1]
     omega( 2) =       0.000000 [THz] =      -0.000007 [cm-1]
     omega( 3) =       0.000000 [THz] =      -0.000004 [cm-1]
     omega( 4) =       0.000000 [THz] =       0.000009 [cm-1]
     omega( 5) =       2.459249 [THz] =      82.031704 [cm-1]
     omega( 6) =       2.716936 [THz] =      90.627231 [cm-1]
     omega( 7) =       2.784694 [THz] =      92.887388 [cm-1]
     omega( 8) =       3.192872 [THz] =     106.502734 [cm-1]
     omega( 9) =       3.212233 [THz] =     107.148552 [cm-1]
     omega(10) =       3.587636 [THz] =     119.670670 [cm-1]
     omega(11) =       4.083911 [THz] =     136.224619 [cm-1]
     omega(12) =       4.768755 [THz] =     159.068544 [cm-1]
     omega(13) =       4.975315 [THz] =     165.958655 [cm-1]
     omega(14) =       5.001761 [THz] =     166.840795 [cm-1]
     omega(15) =       6.892673 [THz] =     229.914826 [cm-1]
     omega(16) =       9.192810 [THz] =     306.639122 [cm-1]
     omega(17) =      10.513991 [THz] =     350.708984 [cm-1]
     omega(18) =      10.524789 [THz] =     351.069187 [cm-1]
     omega(19) =      10.617129 [THz] =     354.149289 [cm-1]
     omega(20) =      10.890637 [THz] =     363.272536 [cm-1]
     omega(21) =      10.905409 [THz] =     363.765293 [cm-1]
     omega(22) =      11.336427 [THz] =     378.142495 [cm-1]
     omega(23) =      11.410636 [THz] =     380.617853 [cm-1]
     omega(24) =      12.077304 [THz] =     402.855485 [cm-1]
     omega(25) =      12.779812 [THz] =     426.288628 [cm-1]
     omega(26) =      13.755479 [THz] =     458.833378 [cm-1]
     omega(27) =      13.984813 [THz] =     466.483148 [cm-1]
     omega(28) =      14.013973 [THz] =     467.455822 [cm-1]
     omega(29) =      14.472678 [THz] =     482.756590 [cm-1]
     omega(30) =      14.500082 [THz] =     483.670669 [cm-1]
     omega(31) =      14.502298 [THz] =     483.744595 [cm-1]
     omega(32) =      15.827998 [THz] =     527.965169 [cm-1]
     omega(33) =      16.083377 [THz] =     536.483716 [cm-1]
     omega(34) =      16.199758 [THz] =     540.365751 [cm-1]
     omega(35) =      17.040062 [THz] =     568.395277 [cm-1]
     omega(36) =      17.466808 [THz] =     582.630011 [cm-1]
     omega(37) =      17.475967 [THz] =     582.935527 [cm-1]
     omega(38) =      17.498416 [THz] =     583.684314 [cm-1]
     omega(39) =      18.422937 [THz] =     614.523039 [cm-1]
     omega(40) =      18.759100 [THz] =     625.736209 [cm-1]
     omega(41) =      18.770115 [THz] =     626.103635 [cm-1]
     omega(42) =      18.827539 [THz] =     628.019117 [cm-1]
     omega(43) =      19.699527 [THz] =     657.105484 [cm-1]
     omega(44) =      20.041762 [THz] =     668.521221 [cm-1]
     omega(45) =      20.150555 [THz] =     672.150180 [cm-1]
     omega(46) =      20.221413 [THz] =     674.513735 [cm-1]
     omega(47) =      20.393150 [THz] =     680.242262 [cm-1]
     omega(48) =      25.687718 [THz] =     856.850025 [cm-1]
     omega(49) =      25.754448 [THz] =     859.075915 [cm-1]
     omega(50) =      25.813670 [THz] =     861.051362 [cm-1]
     omega(51) =      26.069795 [THz] =     869.594747 [cm-1]
     omega(52) =      62.141810 [THz] =    2072.827649 [cm-1]
     omega(53) =      62.166180 [THz] =    2073.640558 [cm-1]
     omega(54) =      62.177946 [THz] =    2074.033021 [cm-1]
     omega(55) =      62.184502 [THz] =    2074.251710 [cm-1]
     omega(56) =      62.706748 [THz] =    2091.671971 [cm-1]
     omega(57) =      62.798498 [THz] =    2094.732409 [cm-1]
     omega(58) =      62.839612 [THz] =    2096.103848 [cm-1]
     omega(59) =      62.929713 [THz] =    2099.109272 [cm-1]
     omega(60) =      63.241959 [THz] =    2109.524671 [cm-1]
     omega(61) =      63.254255 [THz] =    2109.934849 [cm-1]
     omega(62) =      63.262039 [THz] =    2110.194482 [cm-1]
     omega(63) =      63.281137 [THz] =    2110.831535 [cm-1]


matdyn output (100.freq811)
-------------------
 &plot nbnd=  63, nks=   1 /
            0.000000  0.000000  0.000000
   -5.6995   -3.2089   -3.1656   -3.0713   83.7567   91.1907
   93.4933  106.4343  107.0925  118.3760  136.2249  159.4278
  165.9240  166.8070  229.9149  306.6390  350.6441  351.0409
  353.1550  363.4662  364.2095  377.9400  380.4193  403.0923
  426.2896  458.8340  466.4741  467.4453  482.6640  483.6529
  483.7281  527.9141  536.4779  540.3593  568.4037  582.6261
  582.9450  584.5624  614.5306  625.6785  626.0435  628.0315
  656.6387  668.5283  672.4869  674.8514  680.2558  856.8591
  859.0162  860.9915  869.6037 2072.8527 2073.6655 2074.0580
 2074.2786 2091.6973 2094.7864 2096.1588 2099.1353 2109.4521
 2109.9082 2110.1687 2110.8971
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