崩溃了都……
我做了半天发先自己的模型好像完全建错了！
请问该怎么样构建一个纳米杆模型？
比如我想建一个 铜的纳米杆模型4a*4a*40a。  我直接调出铜的晶包模型 然后该怎么构成一个这样的杆件呢？
我现在才发现我原先只是在display style里 将A B C数值改了，虽然是显示出了铜杆，但实际进行模拟计算的是单个晶包……
我想过构建一个super cell 弄成4*4*40的大晶包 可这样是不是不对 ，晶包之间还是应该有作用力的吧。
想请大家帮帮忙 指点下该怎么构建一个铜杆 并且可以作为一个体系进行模拟计算

As you said first build 4*4*40的大晶包, then you need select symmetry as  'No peridodic supercell', following this, you rebuild the cell as large as possible.

我还想问下 建立super-cell  和 建立 non-periodic structure 之间有什么区别 为什么 这里要用 non-periodic 呢

Just build one, and see the difference!
When you rebuild the cell, you need set the AB larger, such as 20*20, then you have vacuum for the PBC

i really appreciate your suggestion!.
actually i have tried once, you know, it is indeed defferent with the one before.   i...uh... just .. you see, i just get confused with these two concept,  for i am not familiar with the relatied knowledge.

thanks ,  again.

and here it goes

when i choose the "non-periodic superstructure" , i find it cannot be rebuild anymore, the size is unchanged just as before we set symmetry.

and another question.
if we choos the "non- periodic superstructure", is it mean not to consider the periodic attribute?  or there is no need to consider the relationship between each cristay cube?

thank you for application

to make sure that you understand, i say a little more.
If you want so simulate the Nano-line or so on, you have to build the cell with the vacuum or using the no-periodic cell. Or it is not Nano-line but just bulk!

(a)You need set New ABC what you want, and you can change the symmetry as you want.
(b)it just means to tell you how to add the vacuum. It is still Periodic Boundary conditions.

thank you for your advices.
i have got some ideas and i am still tryng.
but, you know what, not defense, if i follow your suggestion completely, i will not get the final result. if we build the stick-like crystal such as 4*4*40 first and choose the "non-periodic superstructure", it turns out that we cannot set anything to change the size of the stick, not mention to add vaccum. i just wonder how did you do it  !  maybe you just got some careless mistakes.  so, if you have seconds, i beg you try again and you will find some details you missed, of course i know,  you must have done it before.

so here is a suggestion for you,  also not defense but sincerely.  i think it is not a better way to practice your english when you try to explain some thing, especially such as concepts , methods and something like, to other one. maybe you just suppose everyone has a deeper background as you have. so why not just use chinese?

yours   sincerely  The-Tropic-of-Capricorn

[ 本帖最后由 楠回归线 于 2008-9-6 09:43 编辑 ]

sorry, i do not want to practise English, not necessory.  I can read Chinese.Is this what you want?

i am so sorry for misunderstanding your situation to use English.
i apologize for my rudeness to you. you know , i just have been a hurry since the deadline is coming and i cannot make a sence of your suggestion, probably because i am a rookie and i do not study in this area, when you said to add vacuum or refer to PBD , i have no idea. so when you use English, i become a little... such as out of control or something like.
actually, following your suggestion i tried to  re-simulate the model all the time, and here i  get one as below
  but i don't know is it really like yours
i think i'd better describel the procedure. if you have minutes, please do some judgement, maybe it will be helpful to all the people.
开始时先建立super cell 比如2*2*10
然后仍然在symmetry里选 non-periodic superstructure
再在Crystals里build crystal 然后重新设定a b c
不知道是不是这样就可以了。
也许上面步骤也是有问题的 请指正

另外我曾在别人的论文中看到过模拟出4.5*4.5*75的铜杆，但是supercell 设置的ＡB都是整数阿

谢谢你再次指教

我想我一定是做错了…… 我这个模型完全不能用discover计算 无法 minimizer
i am totaly get confused…………

The structure seems right
(a)'Supercell 设置的ＡB都是整数', you can set whatever you want

但是这个模型不能进行计算阿 您有没有看看我的步骤 是不是哪地方出错了？
而且 老实说 铜与铜之间多出了很多健 一旦计算 都会提示出错
Error: Energy expression: cannot find parameters for bond: Cu1(cu_m)-Cu41(cu_m)
全都是这样的错误……

All steps that you build the model are right.
But you should know that building model and calculation are two different things.
Now, you should ask  someone, excel in discover, to solve the new question