[Pw_forum] 答复: Problem on HSE bandgap caluculation

Thu Jun 15 11:19:02 CEST 2017

Thank for you reply.

From the experimental results, bulk are semi-metal.

Other DFT method with HSE show the band gap of monolayer is 2.0eV.

When I use PBE functional, the gap is 1.6eV which is agreed well with other calculation with PBE method.

Best regards,

Clarence

________________________________
发件人: pw_forum-bounces at pwscf.org <pw_forum-bounces at pwscf.org> 代表 sanjaynayak at jncasr.ac.in <sanjaynayak at jncasr.ac.in>
发送时间: 2017年6月15日 16:52:34
收件人: PWSCF Forum
主题: Re: [Pw_forum] Problem on HSE bandgap caluculation

First check the band-structure in bulk case. The smaller band-gap may be
due to appearance of surface states in band-gap region.

----- Original Message -----
From: "LEUNG Clarence" <liangxy123 at hotmail.com>
To: "pw forum" <pw_forum at pwscf.org>
Sent: Thursday, June 15, 2017 1:55:03 PM
Subject: [Pw_forum] Problem on HSE bandgap caluculation

Dear All,

Now, I want to use HSE functional to calculate the band structure of monolayer arsenic, but the band gap is much smaller than previous report (2eV).

I have try to change some parameters. But the results are not good.

EXX= 0.25, ecutwfc=30, gap=1.15eV,

EXX=0.35, ecutwfc=30, gap=0.89eV,

EXX=0.15, ecutwfc=30, gap=1.40eV,

EXX=0.10, ecutwfc=30, gap=1.56eV,

EXX=0.05, ecutwfc=30, gap=1.63eV,

EXX=0.25, ecutwfc=60, gap=1.15eV,

The psudo-potential is norm-conserving:

As 74.921600d0 As.pbe-mt_fhi.UPF

And the input file as follow:

&CONTROL
calculation='scf' ,

verbosity='low',
etot_conv_thr = 1.0D-5 ,
forc_conv_thr = 1.0D-4 ,
nstep = 200 ,
tstress = .false. ,
tprnfor = .false. ,
max_seconds = 320000 ,
wf_collect = .true. ,
/

&SYSTEM
ibrav=0,
celldm(1)=27.2266448794d0,
nat=32,
ntyp=1,
ecutwfc=30,
input_dft='hse',
occupations='smearing',
smearing = 'gaussian' ,
degauss = 0.02 ,
nosym = .true. ,
vdw_corr = 'DFT-D' ,
nqx1 = 1,
nqx2 = 1 ,
nqx3 = 1 ,
exx_fraction = 0.05,
/

&ELECTRONS
conv_thr=1d-06,
mixing_beta=0.3d0,
electron_maxstep = 1000 ,
/
&IONS
ion_dynamics = 'bfgs',
bfgs_ndim = 3 ,
/
ATOMIC_SPECIES
As 74.921600d0 As.pbe-mt_fhi.UPF

ATOMIC_POSITIONS {crystal}
As 0.083333304 0.041666531 0.465177578
As 0.166666686 0.208333294 0.534822422
As 0.083333418 0.291666706 0.465177578
As 0.166666800 0.458333469 0.534822384
As 0.333333200 0.041666531 0.465177578
As 0.416666582 0.208333294 0.534822422
As 0.333333366 0.291666706 0.465177578
As 0.416666748 0.458333469 0.534822384
As 0.083333304 0.541666531 0.465177578
As 0.166666686 0.708333294 0.534822422
As 0.083333418 0.791666706 0.465177578
As 0.166666800 0.958333469 0.534822384
As 0.333333200 0.541666531 0.465177578
As 0.416666582 0.708333294 0.534822422
As 0.333333366 0.791666706 0.465177578
As 0.416666748 0.958333469 0.534822384
As 0.583333304 0.041666531 0.465177578
As 0.666666686 0.208333294 0.534822422
As 0.583333418 0.291666706 0.465177578
As 0.666666800 0.458333469 0.534822384
As 0.833333200 0.041666531 0.465177578
As 0.916666582 0.208333294 0.534822422
As 0.833333366 0.291666706 0.465177578
As 0.916666748 0.458333469 0.534822384
As 0.583333304 0.541666531 0.465177578
As 0.666666686 0.708333294 0.534822422
As 0.583333418 0.791666706 0.465177578
As 0.666666800 0.958333469 0.534822384
As 0.833333200 0.541666531 0.465177578
As 0.916666582 0.708333294 0.534822422
As 0.833333366 0.791666706 0.465177578
As 0.916666748 0.958333469 0.534822384

K_POINTS
84
0.0000000 0.0000000 0.0000000 0.03125
0.0000000 0.1443377 0.0000000 0.06250
0.0000000 0.2886754 0.0000000 0.06250
0.0000000 0.4330131 0.0000000 0.06250
0.0000000 -0.5773508 0.0000000 0.03125
0.1250000 0.0721689 0.0000000 0.0625
0.1250000 0.2165066 0.0000000 0.0625
0.1250000 0.3608443 0.0000000 0.0625
0.1250000 0.5051820 0.0000000 0.0625
0.1250000 -0.5051820 0.0000000 0.0625
0.1250000 -0.3608443 0.0000000 0.0625
0.1250000 -0.2165066 0.0000000 0.0625
0.1250000 -0.0721689 0.0000000 0.0625
0.2500000 0.1443377 0.0000000 0.0625
0.2500000 0.2886754 0.0000000 0.0625
0.2500000 0.4330131 0.0000000 0.0625
0.2500000 0.5773508 0.0000000 0.0625
0.2500000 -0.4330131 0.0000000 0.0625
0.2500000 -0.2886754 0.0000000 0.0625
0.2500000 -0.1443377 0.0000000 0.0625
0.2500000 0.0000000 0.0000000 0.0625
0.3750000 0.2165066 0.0000000 0.0625
0.3750000 0.3608443 0.0000000 0.0625
0.3750000 0.5051820 0.0000000 0.0625
0.3750000 0.6495197 0.0000000 0.0625
0.3750000 -0.3608443 0.0000000 0.0625
0.3750000 -0.2165066 0.0000000 0.0625
0.3750000 -0.0721689 0.0000000 0.0625
0.3750000 0.0721689 0.0000000 0.0625
-0.500000 -0.2886754 0.0000000 0.03125
-0.500000 -0.1443377 0.0000000 0.0625
-0.500000 0.0000000 0.0000000 0.0625
-0.500000 0.1443377 0.0000000 0.0625
-0.500000 -0.8660262 0.0000000 0.03125
0.0000000000 0.0000000000 0.0000000000 0
0.0277777778 0.0000000000 0.0000000000 0
0.0555555556 0.0000000000 0.0000000000 0
0.0833333333 0.0000000000 0.0000000000 0
0.1111111111 0.0000000000 0.0000000000 0
0.1388888889 0.0000000000 0.0000000000 0
0.1666666667 0.0000000000 0.0000000000 0
0.1944444444 0.0000000000 0.0000000000 0
0.2222222222 0.0000000000 0.0000000000 0
0.2500000000 0.0000000000 0.0000000000 0
0.2777777778 0.0000000000 0.0000000000 0
0.3055555556 0.0000000000 0.0000000000 0
0.3333333333 0.0000000000 0.0000000000 0
0.3611111111 0.0000000000 0.0000000000 0
0.3888888889 0.0000000000 0.0000000000 0
0.4166666667 0.0000000000 0.0000000000 0
0.4444444444 0.0000000000 0.0000000000 0
0.4722222222 0.0000000000 0.0000000000 0
0.5000000000 0.0000000000 0.0000000000 0
0.4833330000 0.0333330000 0.0000000000 0
0.4666660000 0.0666660000 0.0000000000 0
0.4499990000 0.0999990000 0.0000000000 0
0.4333320000 0.1333320000 0.0000000000 0
0.4166650000 0.1666650000 0.0000000000 0
0.3999980000 0.1999980000 0.0000000000 0
0.3833310000 0.2333310000 0.0000000000 0
0.3666640000 0.2666640000 0.0000000000 0
0.3499970000 0.2999970000 0.0000000000 0
0.3333300000 0.3333300000 0.0000000000 0
0.3174571429 0.3174571429 0.0000000000 0
0.3015842857 0.3015842857 0.0000000000 0
0.2857114286 0.2857114286 0.0000000000 0
0.2698385714 0.2698385714 0.0000000000 0
0.2539657143 0.2539657143 0.0000000000 0
0.2380928571 0.2380928571 0.0000000000 0
0.2222200000 0.2222200000 0.0000000000 0
0.2063471429 0.2063471429 0.0000000000 0
0.1904742857 0.1904742857 0.0000000000 0
0.1746014286 0.1746014286 0.0000000000 0
0.1587285714 0.1587285714 0.0000000000 0
0.1428557143 0.1428557143 0.0000000000 0
0.1269828571 0.1269828571 0.0000000000 0
0.1111100000 0.1111100000 0.0000000000 0
0.0952371429 0.0952371429 0.0000000000 0
0.0793642857 0.0793642857 0.0000000000 0
0.0634914286 0.0634914286 0.0000000000 0
0.0476185714 0.0476185714 0.0000000000 0
0.0317457143 0.0317457143 0.0000000000 0
0.0158728571 0.0158728571 0.0000000000 0
0.0000000000 0.0000000000 0.0000000000 0

CELL_PARAMETERS {alat}
1.000000000000d0 0.000000000000d0 0.000000000000d0
-0.500000000000d0 0.866024603476d0 0.000000000000d0
0.000000000000d0 0.000000000000d0 1.388144689097d0

Best regards,
Clarence
CityU university of Hong Kong

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