使用的軟件：VASP, Origin, SshClient, vaspkit.0.51
一 光學性質計算
在完成結構優(yōu)化和靜態(tài)計算后，拷貝 scf 文件夾為 optic
cp -rf scf optic
編輯 optic 文件夾下 INCAR
INCAR
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=xx 為 OUTCAT 中 NBANDS*2, 可使用 grep 命令查詢
grep NBANDS OUTCAR
提交作業(yè)，計算完成后，可查看 OUTCAR 文件，有計算得出介電常數(shù) (Dielectric constant) 的實部和虛部。
frequency dependent IMAGINARY DIELECTRIC FUNCTION (independent particle, no local field effects)
E(ev) X Y Z XY YZ ZX
frequency dependent REAL DIELECTRIC FUNCTION (independent particle, no local field effects)
E(ev) X Y Z XY YZ ZX
使用 vaspkit 程序對計算結果進行處理。
二 vaspkit 的安裝與使用
安裝 Installation
使用 SshClient 將已下載的 vaspkit 導入 linux 服務器，安裝步驟：
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
設置環(huán)境變量
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.
光學數(shù)據(jù)處理
輸入命令opt產(chǎn)生 REAL.IN 和 IMAG.IN 文件，依次輸入命令kit和51，屏幕顯示如下
+---------------------------------------------------+
| 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 (^.^) |
+---------------------------------------------------+
輸出文件 ABSORB.dat，REFRACTIVE.dat，REFLECTIVITY.dat，EXTINCTION.dat 和 ENERGYLOSSSPECTRUM.dat，依次為 absorption coefficient, refractive coefficient, reflectivity coefficient, extinction coefficient and energy-loss function。導出使用 Origin 作圖即可。
附：相關光學性質計算公式
