File: dynevs.f90

package info (click to toggle)
elkcode 5.4.24-2
  • links: PTS, VCS
  • area: main
  • in suites: buster, sid
  • size: 12,840 kB
  • sloc: f90: 48,415; fortran: 22,457; perl: 965; makefile: 384; sh: 369; python: 105; ansic: 67
file content (42 lines) | stat: -rw-r--r-- 916 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

! Copyright (C) 2014 J. K. Dewhurst, S. Sharma and E. K. U. Gross.
! This file is distributed under the terms of the GNU General Public License.
! See the file COPYING for license details.

subroutine dynevs(ev,a,w)
use modmain
use modphonon
implicit none
! arguments
complex(8), intent(in) :: ev(nbph,nbph)
complex(8), intent(in) :: a(nbph,nbph)
real(8), intent(out) :: w(nbph)
! local variables
integer i,j,k
real(8) t1,t2
complex(8) z1
! automatic arrays
real(8) wt(nbph)
! external functions
complex(8) zdotc
external zdotc
! find the eigenvalues and eigenvectors of the matrix a
call eveqnz(nbph,nbph,a,w)
! reorder eigenvalues so that the eigenvectors maximally overlap with ev
wt(:)=w(:)
do i=1,nbph
  j=1
  t1=0.d0
  do k=1,nbph
    z1=zdotc(nbph,ev(:,i),1,a(:,k),1)
    t2=dble(z1)**2+aimag(z1)**2
    if (t2.gt.t1) then
      j=k
      t1=t2
    end if
  end do
  w(i)=wt(j)
end do
return
end subroutine