<br>Dear Prof. Laurence Marks.<br><br>thank you for your favorable reply. I checked and followed your instructions,  installed fftw (with prefix and f77=ifort) successfully. Now, the errors are reduced but  my problem is not solved. now the error coming like this.<br>
<br>fftw_para.o: In function `exec_fftw_para_&#39;:<br>fftw_para.F:(.text+0x77): undefined reference to `fftwnd_f77_mpi_&#39;<br>fftw_para.F:(.text+0xb2): undefined reference to `fftwnd_f77_mpi_&#39;<br>fftw_para.o: In function `init_fftw_para_&#39;:<br>
fftw_para.F:(.text+0x101): undefined reference to `fftw3d_f77_mpi_create_plan_&#39;<br>fftw_para.F:(.text+0x129): undefined reference to `fftw3d_f77_mpi_create_plan_&#39;<br>fftw_para.F:(.text+0x14d): undefined reference to `fftwnd_f77_mpi_local_sizes_&#39;<br>
make[1]: *** [lapw0_mpi] Error 1<br>make[1]: Leaving directory `/home/gvacrc/Wien2k/SRC_lapw0&#39;<br>make: *** [para] Error 2<br><br>please help me once again<br><br>with regards<br>.S.Appalakondaiah<br>