The ABINIT Users Mailing List ( CLOSED )

[张 <zhangting@pku.edu.cn>]

Thanks very much for your help! By using default rprim 
(1,0,0;0,1,0;0,0,1), the code can find a P1 symmetry, thanks a lot! 
your suggestion is very useful.
   My k-point setting is from CASTEP..for I'm also a CASTEP user. In 
CASTEP's settings,this cell(about 15Ax15Ax2.4A) need a 2x2x10's 
mesh,for the k-space grid density probably being 0.03~0.04 
(1/Angstrom).In fact I don't clearly know whether there are 
differences between these two codes in k-space grid representation,
and maybe I don't exactly understand your question yet.Do you mean my 
k-point mesh density is too high or too low? or my unit cell is too 
small? 
   
                                                                       
          Zhang Ting
                                                                       
          Apr.10th 2006


>Hi!
> I also try to optimize the geometry 7_0 CNT but in my case I use 
default value of rprim (1 0 0; 0 1 0; 0 0 1) see my input file and 
sketch of unit cell in attachment. In this case abinit calculates the 
space group base on atoms position. I can advise you use default value 
of rprim and see what happened.  Also, use less value of toldff, your 
calculation will be faster, then you specify more precisely. 
>
> On the other hand I am confused with ngkpt? 
>   Can you explain to my how you choose ngkpt? Why is it 2 2 10, what 
criteria for this?
> 
> 
>
>Yaroslav Shtogun
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