[Pw_forum] fft-check warning

[Ker Park]

Hi QE users,
I am doing the phonon dispersion calculation.While I was running q2r.x, I got a warning "fft-check warning: sum of imaginary terms = ..."Even though I could generate the dispersion without eliminating the warning,the results didn't seem to be correct, and I hope resolving this warning generate the correct one.I've googled this issue, but it seems that the previous postings have been deleted.
I've tried tons of times to get the correct result, but it never happened.Any suggestion will be really appreciated. Below is the output from q2r.x calculation.
Best Regards,
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     Program Q2R v.5.0          starts on 24Nov2012 at  0:55:16 
     This program is part of the open-source Quantum ESPRESSO suite     for quantum simulation of materials; please cite         "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);          URL http://www.quantum-espresso.org",      in publications or presentations arising from this work. More details at     http://www.quantum-espresso.org/quote.php
     Parallel version (MPI), running on     1 processors
     reading grid info from file bite.dyn0  reading force constants from file bite.dyn1 macroscopic fields = T  28.03934   0.00000   0.00000   0.00000  28.03934   0.00000   0.00000   0.00000  19.88834  na=            1  -5.43366   0.00000   0.00000   0.00000  -5.43366   0.00000   0.00000   0.00000  -4.07947  na=            2  -3.93175   0.00000   0.00000   0.00000  -3.93175   0.00000   0.00000   0.00000  -0.83726  na=            3   7.12458   0.00000   0.00000   0.00000   7.12458   0.00000   0.00000   0.00000   3.26273  na=            4   7.09960   0.00000   0.00000   0.00000   7.09960   0.00000   0.00000   0.00000   3.28402  na=            5  -3.96313   0.00000   0.00000   0.00000  -3.96313   0.00000   0.00000   0.00000  -0.86589  nqs=            1 q=   0.00000000  0.00000000  0.00000000  reading force constants from file bite.dyn2  nqs=            6 q=  -0.60777080 -0.35089663  0.08578765 q=   0.60777080  0.35089663 -0.08578765 q=   0.00000000  0.70179327  0.08578765 q=   0.00000000 -0.70179327 -0.08578765 q=   0.60777080 -0.35089663  0.08578765 q=  -0.60777080  0.35089663 -0.08578765  reading force constants from file bite.dyn3  nqs=            3 q=   1.21554160  0.70179327 -0.17157531 q=   0.00000000 -1.40358654 -0.17157531 q=  -1.21554160  0.70179327 -0.17157531  reading force constants from file bite.dyn4  nqs=            6 q=  -0.60777080  0.35089663  0.17157531 q=   0.60777080 -0.35089663 -0.17157531 q=   0.60777080  0.35089663  0.17157531 q=  -0.60777080 -0.35089663 -0.17157531 q=   0.00000000 -0.70179327  0.17157531 q=   0.00000000  0.70179327 -0.17157531  reading force constants from file bite.dyn5  nqs=           12 q=   1.21554160  1.40358654 -0.08578765 q=  -1.21554160 -1.40358654  0.08578765 q=  -0.60777080 -1.75448317 -0.08578765 q=   0.60777080  1.75448317  0.08578765 q=   0.60777080 -1.75448317 -0.08578765 q=  -0.60777080  1.75448317  0.08578765 q=  -1.21554160  1.40358654 -0.08578765 q=   1.21554160 -1.40358654  0.08578765 q=  -1.82331239  0.35089663 -0.08578765 q=   1.82331239 -0.35089663  0.08578765 q=   1.82331239  0.35089663 -0.08578765 q=  -1.82331239 -0.35089663  0.08578765  reading force constants from file bite.dyn6  nqs=            6 q=   0.60777080  1.05268990  0.00000000 q=  -0.60777080 -1.05268990  0.00000000 q=   0.60777080 -1.05268990  0.00000000 q=  -0.60777080  1.05268990  0.00000000 q=  -1.21554160  0.00000000  0.00000000 q=   1.21554160  0.00000000  0.00000000  reading force constants from file bite.dyn7  nqs=            3 q=   1.21554160 -0.70179327 -0.34315061 q=  -1.21554160 -0.70179327 -0.34315061 q=   0.00000000  1.40358654 -0.34315061  reading force constants from file bite.dyn8  nqs=            2 q=   0.00000000  0.00000000  0.25736296 q=   0.00000000  0.00000000 -0.25736296  reading force constants from file bite.dyn9  nqs=            6 q=   1.82331239  1.05268990  0.00000000 q=  -1.82331239 -1.05268990  0.00000000 q=   0.00000000 -2.10537980  0.00000000 q=   0.00000000  2.10537980  0.00000000 q=  -1.82331239  1.05268990  0.00000000 q=   1.82331239 -1.05268990  0.00000000  reading force constants from file bite.dyn10  nqs=            6 q=   1.21554160  0.70179327  0.08578765 q=  -1.21554160 -0.70179327 -0.08578765 q=   0.00000000 -1.40358654  0.08578765 q=   0.00000000  1.40358654 -0.08578765 q=  -1.21554160  0.70179327  0.08578765 q=   1.21554160 -0.70179327 -0.08578765  reading force constants from file bite.dyn11  nqs=            6 q=   1.82331239 -1.05268990 -0.25736296 q=  -1.82331239  1.05268990  0.25736296 q=  -1.82331239 -1.05268990 -0.25736296 q=   1.82331239  1.05268990  0.25736296 q=   0.00000000  2.10537980 -0.25736296 q=   0.00000000 -2.10537980  0.25736296  reading force constants from file bite.dyn12  nqs=            6 q=   1.21554160 -1.40358654 -0.17157531 q=   1.82331239 -0.35089663 -0.17157531 q=  -1.82331239 -0.35089663 -0.17157531 q=  -1.21554160 -1.40358654 -0.17157531 q=   0.60777080  1.75448317 -0.17157531 q=  -0.60777080  1.75448317 -0.17157531  reading force constants from file bite.dyn13  nqs=            1 q=   0.00000000  0.00000000 -0.51472592
      q-space grid ok, #points =   64
      fft-check warning: sum of imaginary terms = .1440955E-09      Q2R          :     0.06s CPU         0.32s WALL
    This run was terminated on:   0:55:16  24Nov2012            
=------------------------------------------------------------------------------=   JOB DONE.=------------------------------------------------------------------------------=
 		 	   		  
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