The ABINIT Users Mailing List ( CLOSED )

["LEE Chin Chai" <cc-lee@imre.a-star.edu.sg>]

Hi HongYi,

To get the rpim vector defined by abinit, you can do a 45 degrees of 
clockwise rotation(you can use a 2D rotation matrix)of the rpim defined in 
the vasp course.  Hope it helps. It is really arbitrary of how you define 
your rpim parameter as long as it reproduces your slab correctly.

Cheers,
chinchai


-----Original Message-----
From: Hongyi Zhao [mailto:hongyi.zhao@gmail.com]
Sent: Thu 4/19/2007 12:22 AM
To: forum@abinit.org
Subject: [abinit-forum] A question about the *rprim* parameter of the fcc's   
 slab along the direction (100).
 
Hi all,

On the page 15 of the following file:

http://phys.cts.nthu.edu.tw/workshop/focus/20060225/VASP-course-2006-2.pdf

I find the slab's *rprim* of FCC's (001) surface should be:

a_1=a(sqrt(2)/2 0 0)
a_2=a(0 sqrt(2)/2 0)
a_3=a(0 0 C)

Where C=D_v/a + m, and D_v is the Vacuum thickness, m is the the number 
of the slab's layer.

But I also find the following URL:

http://www.phy.ccu.edu.tw/~tcleung/Abinit/chapter5.htm

that is corresponding to the abinit's tutorial lesson 4.  In the above 
URL, I find that the slab's *rprim* of FCC's (001) surface is as 
follows:

rprim   0.5 -0.5  0.0  
       0.5  0.5  0.0
       0.0  0.0  C

I think it a lot, but just cann't figure it out, woudl anyone give me 
some hints?

Thanks in advance.

---
Hongyi Zhao
GnuPG DSA: 0xD108493B