<div dir="ltr">

<p class="MsoNormal"><a name="OLE_LINK4"></a><a name="OLE_LINK3"><span style="mso-bookmark:OLE_LINK4"><span style="font-size:8pt;line-height:115%;font-family:"Times New Roman","serif"">Dear Prof.Blaha</span></span></a><span style="font-size:8pt;line-height:115%;font-family:"Times New Roman","serif"">
& Tran</span></p>

<p class="MsoNormal"><span style="font-size:8pt;line-height:115%;font-family:"Times New Roman","serif"">I have calculated static dielectic functions <span style="mso-spacerun:yes"> </span>by YS-PBE0 approximation according your paper(
J. Phys.: Condens. Matter 25 (2013) 435503 (8pp)) , But <span style="mso-spacerun:yes"> </span>static dielectic functions in my case
(KTiOPO4) have different values in 3 directions(εxx≈εyy ≠ εzz).</span></p>

<p class="MsoNormal"><span style="font-size:8pt;line-height:115%;font-family:"Times New Roman","serif""><span style="mso-spacerun:yes"> </span>How do calculate
α(opt)? which ε insert in formula(αopt= 0.147+ 0.634/ε*)? </span></p>

<p class="MsoNormal" style="margin-bottom:0.0001pt;line-height:normal"><span style="font-size:8pt;font-family:"Times New Roman","serif"">Please help me</span></p>

<span style="font-size:8pt;line-height:115%;font-family:"Times New Roman","serif"">Best Regards,</span><br clear="all"><br>-- <br><div class="gmail_signature">Marzieh Ghoohestani<br>PhD Student of Computational Nano Physics<br>Nano Research Center, Department of Physics<br>University of Technology, Isfahan, Iran<br><br></div>
</div>