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_eulerrot
       8             :       use m_judft
       9             : c************************************
      10             : c     Perform Euler rotations.
      11             : c     Y. Mokrousov 
      12             : c
      13             : c     tidied up version
      14             : c     Frank Freimuth
      15             : c************************************
      16             :       contains
      17           8 :       subroutine eulerrot(
      18           8 :      >               nwfs,alpha,beta,gamma,
      19           8 :      <               amx)
      20             : c************************************************************************
      21             : c..Perform "nwfs" Euler rotations.
      22             : c..Input: Set of "nwfs" Euler angles: alpha(i),beta(i),gamma(i); i=1,nwfs
      23             : c..Output: "nwfs" rotation matrices: amx(:,:,i); i=1,nwfs
      24             : c************************************************************************
      25             : 
      26             :       implicit none
      27             : 
      28             :       integer, intent (in)  :: nwfs
      29             :       real,    intent (in)  :: alpha(nwfs),beta(nwfs),gamma(nwfs) 
      30             :       real,    intent (out) :: amx(3,3,nwfs)
      31             : 
      32             :       integer :: nwf
      33             : 
      34           8 :       call timestart("eulerrot")
      35             : 
      36          72 :       do nwf = 1,nwfs
      37             :          call eulerrot1(
      38             :      >                  alpha(nwf),beta(nwf),gamma(nwf),
      39          72 :      <                  amx(1,1,nwf) )
      40             :       enddo 
      41             : 
      42           8 :       call timestop("eulerrot")
      43           8 :       end subroutine eulerrot
      44             : 
      45          64 :       subroutine eulerrot1(
      46             :      >               alpha,beta,gamma,
      47             :      <               amx)
      48             : c***********************************************************************
      49             : c..Perform one Euler rotation.
      50             : c..Input: Euler angles: alpha, beta, gamma
      51             : c..Output: Rotation matrix: amx(:,:)
      52             : c 
      53             : c..Given the Euler angles, the following procedure is 
      54             : c..performed:
      55             : c..1. Rotation around the z-axis by alpha (matrix D)
      56             : c..2. Rotation around the x-axis by beta  (matrix C)
      57             : c..3. Rotation around the z-axis by gamma again. (matrix B)
      58             : c..The overall rotation is given by the matrix A = B*C*D
      59             : c***********************************************************************
      60             : 
      61             :       implicit none
      62             : 
      63             :       real,    intent (in)  :: alpha,beta,gamma 
      64             :       real,    intent (out) :: amx(3,3)
      65             : 
      66             :       real    :: bmx(3,3),cmx(3,3),dmx(3,3),hmx(3,3)
      67             : 
      68          64 :       call timestart("eulerrot1")
      69          64 :       dmx(1,1) = cos(alpha) ; dmx(1,2) = sin(alpha) ; dmx(1,3) = 0. 
      70          64 :       dmx(2,1) =-sin(alpha) ; dmx(2,2) = cos(alpha) ; dmx(2,3) = 0. 
      71          64 :       dmx(3,1) = 0.         ; dmx(3,2) = 0.         ; dmx(3,3) = 1. 
      72             : 
      73          64 :       cmx(1,1) = 1.  ; cmx(1,2) = 0.         ; cmx(1,3) = 0. 
      74          64 :       cmx(2,1) = 0.  ; cmx(2,2) = cos(beta)  ; cmx(2,3) = sin(beta)
      75          64 :       cmx(3,1) = 0.  ; cmx(3,2) =-sin(beta)  ; cmx(3,3) = cos(beta)
      76             :   
      77          64 :       bmx(1,1) = cos(gamma) ; bmx(1,2) = sin(gamma) ; bmx(1,3) = 0. 
      78          64 :       bmx(2,1) =-sin(gamma) ; bmx(2,2) = cos(gamma) ; bmx(2,3) = 0. 
      79          64 :       bmx(3,1) = 0.         ; bmx(3,2) = 0.         ; bmx(3,3) = 1. 
      80             : 
      81        2560 :       hmx = matmul(cmx,dmx)
      82        2560 :       amx = matmul(bmx,hmx)
      83             : 
      84          64 :       call timestop("eulerrot1")
      85          64 :       end subroutine eulerrot1
      86             : 
      87             : 
      88             :       end module m_eulerrot