Line data    Source code

       1             : !--------------------------------------------------------------------------------
       2             : ! Copyright (c) 2016 Peter Grünberg Institut, Forschungszentrum Jülich, Germany
       3             : ! This file is part of FLEUR and available as free software under the conditions
       4             : ! of the MIT license as expressed in the LICENSE file in more detail.
       5             : !--------------------------------------------------------------------------------
       6             : 
       7             :       MODULE m_cylpts
       8             :       CONTAINS
       9           0 :       SUBROUTINE cylpts(x,n,rad)
      10             : c     *********************************************************
      11             : c     YM: generate random points on the cylindrical vacuum boundary
      12             : c     *********************************************************
      13             :       USE m_constants, ONLY : tpi_const
      14             :       USE m_qranf
      15             :       IMPLICIT NONE
      16             : 
      17             :       INTEGER n
      18             :       REAL    rad
      19             :       REAL    x(3,n)
      20             :       REAL    phi,t,tc,y1,x1,xr,yr
      21             :       INTEGER r,j,i
      22             : 
      23             :       INTRINSIC sqrt
      24             : 
      25             :      
      26           0 :       yr = sqrt(7.)
      27             : 
      28           0 :       j = 0
      29             : 
      30           0 :       DO 10 i = 1,n
      31           0 :          x(3,i) = qranf(yr,j) - 0.5
      32           0 :    10 CONTINUE
      33             : 
      34           0 :       j = 0
      35           0 :       xr = sqrt(13.e0)
      36           0 :       yr = sqrt(7.e0)
      37           0 :       DO 20 i = 1,n
      38           0 :          tc = 2.e0*qranf(xr,j) - 1.e0
      39           0 :          phi = tpi_const*qranf(yr,j)
      40             :          t = sqrt(1.e0-tc*tc)
      41           0 :          x1 = cos(phi)
      42           0 :          y1 = sin(phi)
      43           0 :          x(1,i) = rad*x1
      44           0 :          x(2,i) = rad*y1
      45           0 :  20   CONTINUE
      46             : 
      47           0 :       END SUBROUTINE cylpts
      48             :       END MODULE m_cylpts