Dear all,<div><br></div><div>I happened to meet a problem during the e-ph constant calculation.&nbsp;</div><div>When I apply the q2r.x, the calculation of ordinary phonon force constant&nbsp;</div><div>matrix seems OK, but the following step of a2F calculation shows an error</div><div>as follows:</div><div><br></div><div><div>&nbsp; &nbsp;q-space grid ok, #points = &nbsp;100</div><div>&nbsp;</div><div>&nbsp; &nbsp;fft-check warning: sum of imaginary terms = .1593535E-07</div><div><br></div><div>&nbsp; &nbsp;Preparing gamma for a2F</div><div>&nbsp;</div><div>&nbsp;</div><div>&nbsp; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div><div>&nbsp; &nbsp; &nbsp; from init : error # &nbsp; &nbsp; &nbsp; &nbsp; 1</div><div>&nbsp; &nbsp; &nbsp; q not allowed</div><div>&nbsp;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div><div><br></div>What reason causes this error? Any advice I would be very grateful.&nbsp;<h3 class="r" style="font-size: medium; font-weight: normal; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; line-height: 1; overflow-x: hidden; overflow-y: hidden; text-overflow: ellipsis; white-space: nowrap; font-family: arial, sans-serif; "><font color="#dd4b39"><u><br></u></font></h3><div>Best regards,</div><div>Plato Tao</div><div><br></div><br><span><br>--<br>-------------------------------------------------------------------<br>PH.D. candidate Peng Tao <br>Magnetism and Magnetic Materials Division<br>National Laboratory for Material Science<br>Institute of Metal Research, Chinese Academy of Sciences<br>Phone &nbsp;+86-024-83978751<br>-------------------------------------------------------------------</span></div><br><br><br>