VASP 的光学性质计算及 vaspkit 的安装与使用


使用的软件:VASP, Origin, SshClient, vaspkit


一 光学性质计算

在完成结构优化和静态计算后,拷贝 scf 文件夹为 optic

1
cp -rf scf optic

编辑 optic 文件夹下 INCAR

INCAR

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
SYSTEM=x
ISTART=0
ENCUT=350
EDIFF=1E-5
IBRION=-1 # change
POTIM=0.25
NSW=0 # change
EDIFFG=-1E-2
ISMEAR=0
SIGMA=0.05
PREC=ACCURATE
ISIF=2
NPAR=1 # change 4 to 1
#LWAVE=FALSE
#LCHARG=FALSE
LREAL=Auto
#IALGO=48
ISYM=0
NBANDS=x # add
LOPTICS=.TRUE. # add
  • 注:NBANDS=x x 为 OUTCAT 中 NBANDS*2, 可使用 grep 命令查询
1
grep NBANDS OUTCAR

提交作业,计算完成后,可查看 OUTCAR 文件,有计算得出介电常数 (Dielectric constant) 的实部和虚部。

1
2
frequency dependent IMAGINARY DIELECTRIC FUNCTION (independent particle, no local field effects)
E(ev) X Y Z XY YZ ZX

1
2
frequency dependent REAL DIELECTRIC FUNCTION (independent particle, no local field effects)
E(ev) X Y Z XY YZ ZX

使用 vaspkit 程序对计算结果进行处理。

二 vaspkit 的安装与使用

安装 Installation

使用 SshClient 将已下载的 vaspkit 导入 linux 服务器,安装步骤:

1
2
3
4
tar -zvxf vaspkit.*.tar.gz
cd vaspkit.*/src
modify the Makefile file based on your machine environment;
make
  • Note that the formats of POSCAR, CONCAR and CHGCAR files in VASP.5.x are slightly different from those in VASP.4.x. Please set the vasp5=.false. in the src/module.f90 file if you use VASP.4.x

设置环境变量

1
2
3
4
vi ~/.bashrc
alias opt="~/software/vaspkit.0.51/examples/optic/optics.sh"
alias kit="~/software/vaspkit.0.51/src/vaspkit"
source ~/.bashrc
  • You need to preparethe REAL.IN and IMAG.IN files which include the real and imaginary parts of frequencydependent complex dielectric function. There is a bash script optics.sh as a reference in the vaspkit.*/examples/optic/ could help you to prepare the real.in and imag.in files.

光学数据处理

输入命令opt产生 REAL.INIMAG.IN 文件,依次输入命令kit51,屏幕显示如下

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
+---------------------------------------------------+
| VASPKIT Version: 0.51 (10 Oct. 2016) |
| A Postprocessing Toolkit For VASP.5.x Code |
| Developed By Vei WANG (wangvei@icloud.com) |
+---------------------------------------------------+
=============== Structural Options ==================
2) Elastic Constant Calculator
3) Structure Converting 4) Supercell Building
5) EOS Fitting 6) Symmetry Toolkit
7) K-Mesh Generating
8) Band-Structure Path Generating (experimental)
=============== Electronic Options ==================
11) Total DOS 12) Projected DOS
13) l-m Decomposed DOS
21) Band-Structure 22) Projected Band-Structure
23) 3D Band-Structure for Two-Dimensional Materials
24) One Specific Band-Structure
======== Charge Density & Potential Options =========
31) CHG Density 32) Spin Density
33) Spin-Up & -Down Density
34) CHG Difference 35) Spin Density Difference
41) Planar-Average CHG 42) Planar-Average POT
=============== Optical Options =====================
51) Linear Optics
================ Misc Utilities =====================
91) Semiconductor Calculator
92) VASP2BoltzTraP
0) Quit
------------>>
51
+---------------------------------------------------+
| Please prepared IMAG.in and REAL.in files |
| before runing optics |
|...................................................|
| Calculate absorb,refractive,energylossspectrum, |
| extinctionr and reflectivity (in eV). |
+---------------------------------------------------+
-->> (1) Reading IMAG.in and REAL.in Files...
-->> (2) Written Optical Files Succesfully!
+---------------------------------------------------+
| * DISCLAIMER * |
| CANNOT Guarantee Reliability of VASPKIT Code |
| CHECK Your Results for Consistency If Necessary |
| (^.^) GOOD LUCK (^.^) |
+---------------------------------------------------+

输出文件 ABSORB.dat,REFRACTIVE.dat,REFLECTIVITY.dat,EXTINCTION.dat 和 ENERGYLOSSSPECTRUM.dat,依次为 absorption coefficient, refractive coefficient, reflectivity coefficient, extinction coefficient and energy-loss function。导出使用 Origin 作图即可。


附:相关光学性质计算公式

Compartir Comentarios