[Pw_forum] ABINIT-QE conversion

Jan Gryko gryko at jsu.edu
Wed May 5 16:31:49 CEST 2010


 Hello,

 I am trying to convert ABINIT files into QE using QE-ABINIT Perl script.  Attached are: Abinit input (Na6Si34.inp)
 and converted QE file Na6Si34.pw.in.  I had to modify Na6Si34.pw.in by adding Na and Si symbols, as the Perl 
 script  does not recognize atom types.  However, inspecting Na6Si34.pw.in with xcrysden file I see that
 atomic positions are incorrect.  
 Even correcting CELL_PARAMETERS (last line should be probably 0.5 0.5 0, instead of 0.5 0 0, am I
 correct?) results in an incorrect structure.  I also tried to directly specify trigonal lattice,
 ibrav = 5
 celldm(1) = 19.536 
 celldm(4) = 0.5  

 but the resulting atomic positions are also incorrect. The cell coordinates in the ABINIT file are 
 obtained using PowderCell free program, by transforming space group 227,setting 1 into trigonal
 group 166, setting 2, i.e. transforming cubic a,b,c, axes into A=1/2(b+c), B=1/2(a+c) C=1/2(a+b) and
 shifting origin by (-1/8, -1/8, -1/8). 

 Reading INPUT_PW Doc file I see that trigonal axes used by QE are 
 v1 = a(tx,-ty,tz), v2 = a(0,2ty,tz), v3 = a(-tx,-ty,tz).   Shall I transform my coordinates into 
 the (v1, v2, v3) axes?

 Thank you for your advice,

Jan Gryko 
Jacksonville State University 
232-C Martin Hall 
Jacksonville, Al 36265 
256-782-5218 
256-782-5336 fax 



More information about the users mailing list