[CPMD-list] About CELL keyword

[oulihui666]

Hi All,

Recently, I have the following questions about the parameters for the CELL keyword, I'm trying to use CPMD simulating the Pt(111) slab. In my input file, Pt(111) slab contains 3 layers and 12 Pt atoms, 12Ǻ layer of vacuum. SYSTEM was setted as follows:

 

&SYSTEM

   POINT GROUP

    AUTO

   SYMMETRY

    4

   CELL

    5.549    1    2.979     -0.5  0.0  0.0 

   CUTOFF

    30.000

   ANGSTROM

   KPOINTS MONKHORST-PACK fULL

    4  4  1

&END

 In CELL, The parameters specifying the super cell are read from the next line. Six numbers in the following order have to be provided: a, b/a, c/a, cos(alpha), cos(beta), cos(gamm). Where  alpha is the angle between axis a and b, beta is the angle between axis a and c, gamm is the angle between axis b and c. In all of them,a, b, c iscrystallographic constants, In my system, a=5.549Ǻ, b=5.549Ǻ, c=16.531Ǻ, alpha=120, beta=90,gamm=90. So, in CELL, I have setted a=5.549, b/a=1, c/a=2.979, cos(alpha)=-0.5, cos(beta)=0, cos(gamm)=0. However, when I calculated, displayed an error, It displayed as follows: SUPERCELL DOES NOT MATCH SYMMETRY. I am confused, andhope to obtain your help, any suggestion is appreciated.

 

Thank you in advance

Best wishes

Lihui Ou

 

 
 
 
 

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Lihui Ou
PH.D Candidate in Electrochemistry                      
College of Chemistry and Molecular Science            
Wuhan University,430072,Hubei Province,China 
E-mail:oulihui666 at 126.com
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