anchor.diff:  '    0.0000    0.0000    0.0000    0.0000    0.5574    0.0000',&
   '    0.0000    0.0000    0.0000    0.0000    0.0000    0.5574'
   
  +   CCexp = 1.d7 * reshape( &
  +   (/  3.2634,  0.9878,  0.9878,  0.0000,  0.0000,  0.0000, &
  +       0.9878,  3.3358,  0.9784,  0.0000,  0.0000,  0.0000, &
  +       0.9878,  0.9784,  3.3358,  0.0000,  0.0000,  0.0000, &
  +       0.0000,  0.0000,  0.0000,  1.1787,  0.0000,  0.0000, &
  +       0.0000,  0.0000,  0.0000,  0.0000,  0.5574,  0.0000, &
  +       0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.5574  /), (/6,6/))
  +
      write(*,'(/a)') 'Output: (x10^7)'
      write(*,'(6f10.4)') CC/1.d7
      
  +   ! Different if any value differs by more than 0.1 %
  +   if (any(abs(CC - CCexp) > abs(CCexp/1.d4))) then
  +      write(*,'(/a,e10.4)') 'TEST FAILED: total difference between sum of matrices = ',sum(abs(CC-CCexp))
  +   else
  +      write(*,'(/a)') 'Test passed'
  +   endif
   
   end program test_CIJ_tandon_and_weng
positive.code: 
        real(rs), parameter :: big_number = 10.e36 ;      
  
     real(rs)   :: CC(6,6),vp,vs,rho,vpi,vsi,rhoi,c,del
     
     vp = 5.8d3
     vs = 3.46d3
  
negative.code:    vsi = 0.d0
     rhoi = 2.2d3
  
     call CIJ_tandon_and_weng(vp,vs,rho,del,c,vpi,vsi,rhoi,CC,rhoout)
     
     write(*,'(a)')  'Output should look like: (x10^7)'
     write(*,'(a)') &
  