[Pw_forum] Question on Construction of Cu(111) surface

[degironc]

ATOMIC_POSITIONS alat
means that what follows are atomic positions in CARTESIAN COORDINATES in 
units of
alat  (i.e. celldm(1))
ATOMIC_POSITIONS crystal
means atomic positions given in crystal coordinates (i.e: as fraction of 
the fundamental lattice vectors).

Your positions look like "crystal" one except that the third component 
(fraction along at_3)
is certainly wrong and should be divided, i guess,  by celldm(3) (i.e. c/a)

stefano



Clark Lee wrote:

> Dear all,
> I aimed to construct a five-layered Cu(111) surface of (3*3) size, by 
> the following atomic positions(ibrav=4). But the XCRYSDEN visualized  
> model was totally not the surface with hexagonal symmetry that i 
> expected. Any idea about the right construction of (111) surfaces?
>  
> ATOMIC_POSITIONS alat
>    Cu      0.000000000    0.000000000    1.633014073   
>    Cu      0.333333333    0.000000000    1.633014073  
>    Cu      0.666666667    0.000000000    1.633014073  
>    Cu      0.000000000    0.333333333    1.633014073  
>    Cu      0.333333333    0.333333333    1.633014073  
>    Cu      0.666666667    0.333333333    1.633014073   
>    Cu      0.000000000    0.666666667    1.633014073    
>    Cu      0.333333333    0.666666667    1.633014073   
>    Cu      0.666666667    0.666666667    1.633014073   
>    Cu      0.222222222    0.222222222    1.224760555  
>    Cu      0.555555555    0.222222222    1.224760555  
>    Cu      0.888888888    0.222222222    1.224760555  
>    Cu      0.222222222    0.555555555    1.224760555   
>    Cu      0.555555555    0.555555555    1.224760555   
>    Cu      0.888888888    0.555555555    1.224760555  
>    Cu      0.222222222    0.888888888    1.224760555   
>    Cu      0.555555555    0.888888888    1.224760555   
>    Cu      0.888888888    0.888888888    1.224760555   
>    Cu      0.111111111    0.111111111    0.816507036  
>    Cu      0.444444444    0.111111111    0.816507036  
>    Cu      0.777777777    0.111111111    0.816507036   
>    Cu      0.111111111    0.444444444    0.816507036   
>    Cu      0.444444444    0.444444444    0.816507036   
>    Cu      0.777777777    0.444444444    0.816507036   
>    Cu      0.111111111    0.777777777    0.816507036   
>    Cu      0.444444444    0.777777777     0.816507036   
>    Cu      0.777777777    0.777777777    0.816507036   
>    Cu      0.000000000    0.000000000    0.408253518   
>    Cu      0.333333333    0.000000000    0.408253518   
>    Cu      0.666666667     0.000000000    0.408253518   
>    Cu      0.000000000    0.333333333    0.408253518   
>    Cu      0.333333333    0.333333333    0.408253518   
>    Cu      0.666666667    0.333333333    0.408253518   
>    Cu      0.000000000    0.666666667    0.408253518   
>    Cu      0.333333333    0.666666667    0.408253518   
>    Cu      0.666666667    0.666666667    0.408253518   
>    Cu      0.222222222    0.222222222    0.000000000    
>    Cu      0.555555555    0.222222222    0.000000000   
>    Cu      0.888888888    0.222222222    0.000000000   
>    Cu      0.222222222    0.555555555    0.000000000   
>    Cu      0.555555555    0.555555555     0.000000000   
>    Cu      0.888888888    0.555555555    0.000000000    
>    Cu      0.222222222    0.888888888    0.000000000   
>    Cu      0.555555555    0.888888888    0.000000000   
>    Cu      0.888888888     0.888888888    0.000000000
>  
>