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wuli8

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I want to plot Band structure by use
Case.Spaghetti_ene file but I don't know, what are the five columns in this
file? Could you please let me know, how can I plot Band structure by
Case.Spaghrtti_ene file and or other files?

Answer
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The first three columns correspond to coordinates of the particular k-point,
the 4th column is the total distance of your path in the k-space, and the
last column is the actual energy corresponding to this k-point and energy
band. Bands are listed below each other.

To plot the band structure you need only the 4th and 5th columns. The first
three are there mainly for you orientation and to allow you to label
important points in your band structure correctly.

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121楼2008-12-28 12:04:57
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wysong

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Originally posted by zhangyunli at 2008-12-25 10:43:

好像不行

谢谢你的答复 我是这样做的:首先用FSM初步达到一个反铁磁的自洽结果 然后运行正常的GGA 在这个结果的基础上面我就可以加轨道耦合了 呵呵
122楼2008-12-28 14:56:20
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wuli8

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Originally posted by wysong at 2008-12-28 14:56:



谢谢你的答复 我是这样做的:首先用FSM初步达到一个反铁磁的自洽结果 然后运行正常的GGA 在这个结果的基础上面我就可以加轨道耦合了 呵呵

感谢交流
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123楼2008-12-28 15:05:19
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wuli8

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I read userguide and plot my band structure according to that.
> The process is
> after a successful scf
>   making case.klist_band
>    x lapw1 -band
>    x lapw2 -qtl -band
>    editing case.insp
>    x spaghetti
>    plot ...
>
> my questions:
>
> 1- I saw case.energy but I want to know from which file I can
> calculate band gap and band width exactly  and how.
>
> 2. Is there any difference between  bandstructure of one case with the
> same case.klist_band but different case.klist ?
>

Answer
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1.A possible (probably not the fastest) route is as follows :
   Plot the spaghetti, to start with.
   Get the K0-value at which the gap occurs (eg. GAMMA point)  
   Get EFERMI from case.outputt.
   Examine (eigen)energy values at K0 in case.output1 : The energy
difference between EFERMI and the
   next E value is the required energy gap.
   Similarly, knowing the k-values where band extrema (min,max) occur (
see spaghetti plot),
   you can obtain the bandwidth from examination of E(K) values in
case.output1.

2. YES ! Increasing the case.klist set, in principle, improves accuracy
of SC potential.
    See UG  pg. 19 - "x kgen"

[ Last edited by wuli8 on 2008-12-28 at 17:05 ]
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124楼2008-12-28 17:02:37
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wuli8

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Do you mean I should use the imaginary and real part values in the file
case.epsilon to calculate the reflectivity? Today I tried to calculate the
reflectivity of anatase TiO2, but the obtained values of reflectivity are
less than 35% in the range of 200-900nm. While my experimental values are
more than 80%. What's the matter?

Answer
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> Do you mean I should use the imaginary and real part values
> in the file case.epsilon to calculate the reflectivity?

I mean only what is written at the top of page 131 of the
usersguide.  That is, "All dielectric tensor components can
be found in file case.epsilon[up|dn]."

> Today I tried to calculate the reflectivity of anatase TiO2, but
> the obtained values of reflectivity are less than 35% in the
> range of 200-900nm. While my experimental values are
> more than 80%. What's the matter?

The reflectivity comes after a lot of post-processing.
Why not go back to the more "raw" theoretical results.

I suggest you do the following:
1) find previous DFT-based calculations on anatase TiO2.
One that seems particulary relevant is PRB 51, 13023 (1995).
It even mentions reflectivity calculations.
2) Compare your band structure, DOS and computed dieletric
functions to the ones in the above paper.
3) Check your scissor-shift.  Did you use a scissor shift?  Note
that (for normal incidence) the reflectivity is
        r = (n-1)^2/(n+1)^2.
A scissor shift lowers the value of epsilon(0), which lowers
the theoretical value of the reflectivity.

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125楼2008-12-28 17:23:49
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wysong

金虫 (小有名气)

求助

首先向版主道歉 在这里问一个与使用wien2k无关的问题 呵呵

我想让各为用wien2k的战友们帮忙了解一下 有在兰州的同学吗 兰州有用wien2k或者vasp来做材料设计的研究单位吗  麻烦大家了 呵呵
126楼2008-12-28 19:15:38
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wuli8

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Originally posted by wysong at 2008-12-28 19:15:
首先向版主道歉 在这里问一个与使用wien2k无关的问题 呵呵

我想让各为用wien2k的战友们帮忙了解一下 有在兰州的同学吗 兰州有用wien2k或者vasp来做材料设计的研究单位吗  麻烦大家了 呵呵

127楼2008-12-28 22:28:56
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wysong

金虫 (小有名气)

求助

各位大侠 我想用xcrsden来做电子密度图 看看我的体系是否有轨道有序现象,但是得到的图一直显示是球形 很明显是有问题 我已经在in2文件中按照DOS上显示的能量区间选择了我想要显示原子的区间 不知道该怎么办了 呵呵 有那位高手帮帮忙啊 谢谢了 这个东西很麻烦 能用QQ指点一下吗 我的是292222016 非常感谢!!
128楼2008-12-29 15:36:25
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wax54

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wuli8(金币+5,VIP+0):感谢您的交流!(*^__^*) ……
使用wien2k时候需要的看图工具是不是一共有三个啊,包括
xcrysden:用于查看晶格结构和电荷密度
gnuplot:用于查看DOS和电荷密度
ghostview:用于查看能带结构
斑竹,我的理解是否争取?
129楼2008-12-30 19:39:43
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wax54

铜虫 (小有名气)

打错了,我是想说是否正确?
130楼2008-12-30 19:40:30
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