<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div dir="ltr" data-setdir="false">Dear users and experts</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">I want to calculate the second order interatomic force constant. In my system I have applied spin orbit coupling. In this case in ph.x the matdyn files are in xml format except matdyn0. So how do I write the q2r.in file?</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">With the following q2r.in, it complains about matdyn0, <br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><div> &INPUT<br> fildyn='matdyn.xml',<br> zasr='crystal',<br> flfrc=' espresso.ifc2'<br><div> /</div><div><br></div><div><br></div></div><div dir="ltr" data-setdir="false">when fildyn='matdyn' , it complains about other matdyn1, matdyn2, etc... files.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Can someone please help for this ? Thank you</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">D.<br></div></div></div></body></html>