ABINIT光学计算

简单总结；

http://www.abinit.org/documentation/helpfiles/for-v5.8/users/optic_help.html#3

http://www.abinit.org/documentation/helpfiles/for-v5.8/users/optic_help.html

经过两步计算可以得到介电常数

（1）计算动量矩阵

运行命令abinis < toptic_1.files >& log

分6个小步骤；

1；计算基态能量 SCF--只处理占据能带--自洽计算

2；非自洽计算  NSCF---加大能带；全空间撒点

3；用2的结果 在大能带-全空间 上 产生波函数【可以略去，但是为了加快计算，建议采用】

4-6；为了计算动量矩阵、

以上产生四个 toptic_1o_DS3_WFK, toptic_1o_DS4_1WF7, toptic_1o_DS5_1WF8 and toptic_1o_DS6_1WF9 文件用于光学性质计算

（2）计算光学性质

运行命令optic < toptic_2.files > log &
需要预处理文件，及上面产生的几个文件 ；

                         *_WFK 结尾的基态波函数文件

                         _1WF7 , _1WF8 , and _1WF9 的动量矩阵文件

numbers 3*natom+1, 3*natom+2 and 3*natom+3 natom=2 时尾号为 7，8，9

OPTIC输入文件

A typical optic.files file is presented below :

optic.in     ! Name of input file
optic.out    ! Unused
optic        ! Root name for all files that will be produced

Since very few input parameters are required for Optic, the optic.in file contains them in the following order which must be kept unaltered :

abo_1WF7      ! Name of the first d/dk response wavefunction file, produced by abinit
abo_1WF8      ! Name of the second d/dk response wavefunction file, produced by abinit
abo_1WF9      ! Name of the third d/dk response wavefunction file, produced by abinit
abo_WFK       ! Name of the ground-state wavefunction file, produced by abinit
0.01          ! Value of the *smearing factor*, in Hartree
0.010   1     ! frequency *step* and *maximum* frequency (Ha)
0.000         ! *Scissor* shift if needed, in Hartree
0.001         ! *Tolerance* on closeness of singularities (in Hartree)
3             ! *Number of components* of linear optic tensor to be computed
11 33 23      ! Linear *coefficients* to be computed (x=1, y=2, z=3)
2             ! Number of components of nonlinear optic tensor to be computed
123 222       ! Non-linear coefficients to be computed