[Pw_forum] Binding energy of Cu at CNT

chengyu yang chengyu.young at gmail.com
Sat Oct 22 19:25:13 CEST 2011


Dear every one,
        I am now trying to calculate the binding energy of Cu at CNT,  I used
one cu atom per unit cell, which is cnt (6,6). First I optimized the
structure of cnt and the cu at cnt structure, then I calculated the total
energy of a single cu atom. I make hand calculations after I get all the
total energy result.
       At first I used ultrasoft potential for both cu and cnt, but the
result is about -1.6 ev, much different from around -0.1 ev in the
literature.
      Then I changed the potential to PAW potential, for that is what's used
in the literature,  but it seems that the cu at cnt calculation won't converged
and the calculation goes on for a day and a night.
       I don't know what's the problem, now I am posting my script and hope
anybody could give me some advice. There may be some small error that I
cannot recognize. Thank you beforehand.

Case 1(using uspp):
(1) cnt.in

&CONTROL
      calculation = 'relax'
      restart_mode='from_scratch',
      tstress = .true.
      tprnfor = .true.
      outdir = '/home/student/espresso-4.3.1/tmp/' ,
      pseudo_dir = '/home/student/espresso-4.3.1/pseudo/' ,
      prefix = 'cnt' ,
 /
 &SYSTEM
                       ibrav = 6,celldm(1) =
21.764541128,celldm(3)=0.213765379
                       nat = 24,ntyp = 1,ecutwfc = 35 ,
                     occupations='smearing', smearing='gaussian',
degauss=0.02
 /

 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                    mixing_beta = 0.7 ,
 /
  &IONS
                 bfgs_ndim         = 3,
                 upscale           = 100.D0,
                 pot_extrapolation = "second_order",
                 wfc_extrapolation = "second_order",
/

ATOMIC_SPECIES
    C   12.01100  C.pz-vbc.UPF

ATOMIC_POSITIONS angstrom
  C        4.085165    -0.000000    -1.231010
  C        3.838021     1.399343    -1.231010
  C        3.537856     2.042582     0.000000
  C        2.624152     3.130877     0.000000
  C        2.042582     3.537856    -1.231010
  C        0.707144     4.023496    -1.231010
  C        0.000000     4.085165     0.000000
  C       -1.399343     3.838021     0.000000
  C       -2.042582     3.537856    -1.231010
  C       -3.130877     2.624152    -1.231010
  C       -3.537856     2.042582     0.000000
  C       -4.023496     0.707144     0.000000
  C       -4.085165     0.000000    -1.231010
  C       -3.838021    -1.399343    -1.231010
  C       -3.537856    -2.042582     0.000000
  C       -2.624152    -3.130877     0.000000
  C       -2.042582    -3.537856    -1.231010
  C       -0.707144    -4.023496    -1.231010
  C       -0.000000    -4.085165     0.000000
  C        1.399343    -3.838021     0.000000
  C        2.042582    -3.537856    -1.231010
  C        3.130877    -2.624152    -1.231010
  C        3.537856    -2.042582     0.000000
  C        4.023496    -0.707144     0.000000


K_POINTS automatic
    1 1 5 0 0 0

(2) cucnt.in

&CONTROL
      calculation = 'relax'
      restart_mode='from_scratch',
      tstress = .true.
      tprnfor = .true.
      outdir = '/home/student/espresso-4.3.1/tmp/' ,
      pseudo_dir = '/home/student/espresso-4.3.1/pseudo/' ,
      prefix = 'cntcu' ,
 /

 &SYSTEM
                       ibrav = 6,celldm(1) =
21.764541128,celldm(3)=0.213765379
                       nat = 25,ntyp = 2,ecutwfc = 35 ,
                     occupations='smearing', smearing='gaussian',
degauss=0.02
 /

 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                    mixing_beta = 0.7 ,
 /
 &IONS
                 bfgs_ndim         = 3,
                 upscale           = 100.D0,
                 pot_extrapolation = "second_order",
                 wfc_extrapolation = "second_order",
/
ATOMIC_SPECIES
    C   12.01100  C.pz-vbc.UPF
    Cu  63.55     Cu.pz-d-rrkjus.UPF

ATOMIC_POSITIONS angstrom
  C        4.085165    -0.000000    -1.231010
  C        3.838021     1.399343    -1.231010
  C        3.537856     2.042582     0.000000
  C        2.624152     3.130877     0.000000
  C        2.042582     3.537856    -1.231010
  C        0.707144     4.023496    -1.231010
  C        0.000000     4.085165     0.000000
  C       -1.399343     3.838021     0.000000
  C       -2.042582     3.537856    -1.231010
  C       -3.130877     2.624152    -1.231010
  C       -3.537856     2.042582     0.000000
  C       -4.023496     0.707144     0.000000
  C       -4.085165     0.000000    -1.231010
  C       -3.838021    -1.399343    -1.231010
  C       -3.537856    -2.042582     0.000000
  C       -2.624152    -3.130877     0.000000
  C       -2.042582    -3.537856    -1.231010
  C       -0.707144    -4.023496    -1.231010
  C       -0.000000    -4.085165     0.000000
  C        1.399343    -3.838021     0.000000
  C        2.042582    -3.537856    -1.231010
  C        3.130877    -2.624152    -1.231010
  C        3.537856    -2.042582     0.000000
  C        4.023496    -0.707144     0.000000
  Cu       0            0            0

K_POINTS automatic
    1 1 5 0 0 0


(3) cu.in

&CONTROL
                calculation='scf',
                restart_mode='from_scratch',
                outdir = '/home/student/espresso-4.3.1/tmp/' ,
                pseudo_dir = '/home/student/espresso-4.3.1/pseudo/' ,
                prefix = 'cu' ,
 /
 &SYSTEM
                       ibrav = 1,celldm(1)= 20,
                       nat = 1,ntyp = 1,ecutwfc = 35 ,
                      occupations='smearing', smearing='gaussian',
degauss=0.002
                      nspin = 2,
                      starting_magnetization(1)=0.2
 /

 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                    mixing_beta = 0.3 ,
 /

ATOMIC_SPECIES
  Cu   63.546    Cu.pz-d-rrkjus.UPF

ATOMIC_POSITIONS
Cu   0.000000000   0.000000000   0.000000000

K_POINTS GAMMA

Case 2:(using PAW potential)

(1)cnt.in

&CONTROL
      calculation = 'relax'
      restart_mode='from_scratch',
      tstress = .true.
      tprnfor = .true.
      outdir = '/home/student/espresso-4.3.1/tmp/' ,
      pseudo_dir = '/home/student/espresso-4.3.1/pseudo/' ,
      prefix = 'cnt' ,
 /
 &SYSTEM
                       ibrav = 6,celldm(1) =
21.764541128,celldm(3)=0.213765379
                       nat = 24,ntyp = 1,ecutwfc = 50 ,
                     occupations='smearing', smearing='gaussian',
degauss=0.02
 /

 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                    mixing_beta = 0.7 ,
 /
  &IONS
                 bfgs_ndim         = 3,
                 upscale           = 100.D0,
                 pot_extrapolation = "second_order",
                 wfc_extrapolation = "second_order",
/

ATOMIC_SPECIES
    C   12.01100  C.pbe-mt_gipaw.UPF

ATOMIC_POSITIONS angstrom
  C        4.085165    -0.000000    -1.231010
  C        3.838021     1.399343    -1.231010
  C        3.537856     2.042582     0.000000
  C        2.624152     3.130877     0.000000
  C        2.042582     3.537856    -1.231010
  C        0.707144     4.023496    -1.231010
  C        0.000000     4.085165     0.000000
  C       -1.399343     3.838021     0.000000
  C       -2.042582     3.537856    -1.231010
  C       -3.130877     2.624152    -1.231010
  C       -3.537856     2.042582     0.000000
  C       -4.023496     0.707144     0.000000
  C       -4.085165     0.000000    -1.231010
  C       -3.838021    -1.399343    -1.231010
  C       -3.537856    -2.042582     0.000000
  C       -2.624152    -3.130877     0.000000
  C       -2.042582    -3.537856    -1.231010
  C       -0.707144    -4.023496    -1.231010
  C       -0.000000    -4.085165     0.000000
  C        1.399343    -3.838021     0.000000
  C        2.042582    -3.537856    -1.231010
  C        3.130877    -2.624152    -1.231010
  C        3.537856    -2.042582     0.000000
  C        4.023496    -0.707144     0.000000


K_POINTS automatic
    1 1 5 0 0 0

(2) cucnt.in

&CONTROL
      calculation = 'relax'
      restart_mode='from_scratch',
      tstress = .true.
      tprnfor = .true.
      outdir = '/home/student/espresso-4.3.1/tmp/' ,
      pseudo_dir = '/home/student/espresso-4.3.1/pseudo/' ,
      prefix = 'cntcu' ,
 /

 &SYSTEM
                       ibrav = 6,celldm(1) =
21.764541128,celldm(3)=0.213765379
                       nat = 25,ntyp = 2,ecutwfc = 50 ,
                     occupations='smearing', smearing='gaussian',
degauss=0.02
 /

 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                    mixing_beta = 0.7 ,
 /
 &IONS
                 bfgs_ndim         = 3,
                 upscale           = 100.D0,
                 pot_extrapolation = "second_order",
                 wfc_extrapolation = "second_order",
/
ATOMIC_SPECIES
    C   12.01100  C.pbe-mt_gipaw.UPF
    Cu  63.55     Cu.pbe-paw_kj.UPF

ATOMIC_POSITIONS angstrom
  C        4.085165    -0.000000    -1.231010
  C        3.838021     1.399343    -1.231010
  C        3.537856     2.042582     0.000000
  C        2.624152     3.130877     0.000000
  C        2.042582     3.537856    -1.231010
  C        0.707144     4.023496    -1.231010
  C        0.000000     4.085165     0.000000
  C       -1.399343     3.838021     0.000000
  C       -2.042582     3.537856    -1.231010
  C       -3.130877     2.624152    -1.231010
  C       -3.537856     2.042582     0.000000
  C       -4.023496     0.707144     0.000000
  C       -4.085165     0.000000    -1.231010
  C       -3.838021    -1.399343    -1.231010
  C       -3.537856    -2.042582     0.000000
  C       -2.624152    -3.130877     0.000000
  C       -2.042582    -3.537856    -1.231010
  C       -0.707144    -4.023496    -1.231010
  C       -0.000000    -4.085165     0.000000
  C        1.399343    -3.838021     0.000000
  C        2.042582    -3.537856    -1.231010
  C        3.130877    -2.624152    -1.231010
  C        3.537856    -2.042582     0.000000
  C        4.023496    -0.707144     0.000000
  Cu       0            0            0

K_POINTS automatic
    1 1 5 0 0 0


(3) cu.in


&CONTROL
                calculation='scf',
                restart_mode='from_scratch',
                outdir = '/home/student/espresso-4.3.1/tmp/' ,
                pseudo_dir = '/home/student/espresso-4.3.1/pseudo/' ,
                prefix = 'cu' ,
 /
 &SYSTEM
                       ibrav = 1,celldm(1)= 20,
                       nat = 1,ntyp = 1,ecutwfc = 50 ,
                      occupations='smearing', smearing='gaussian',
degauss=0.002
                      nspin = 2,
                      starting_magnetization(1)=0.2
 /

 &ELECTRONS
                    conv_thr = 1.0d-8 ,
                    mixing_beta = 0.3 ,
 /

ATOMIC_SPECIES
  Cu   63.546     Cu.pbe-paw_kj.UPF

ATOMIC_POSITIONS
Cu   0.000000000   0.000000000   0.000000000

K_POINTS GAMMA




University of Central Florida
MMAE
Chengyu Yang
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