My understanding is that, in the HSE functional, 25% of the short range componet of PBE exchange interaction is replaced with Hartree-Fock exchange, hence in this kind of calculations, you have a non-local orbital dependent Hamiltonian. As a result of that the computations are significantly more expensive that the calculations by using local LDA or semi-local GGA functionals.<br>

<br>Regards<br>SJ Hashemifar<br clear="all"><div>======================================<br>Seyed Javad  Hashemifar<br>Department of Physics, Isfahan University of Technology<br>84156-83111 Isfahan, Iran<br>Tel: +98 311 391 2375     Fax:+98 311 3912376<br>

Email:  <a href="mailto:hashemifar@cc.iut.ac.ir" target="_blank">hashemifar@cc.iut.ac.ir</a><br>Group Homepage:      <a href="http://cmsgroup.iut.ac.ir" target="_blank">http://cmsgroup.iut.ac.ir</a><br>Personal Homepage:  <a href="http://hashemifar.iut.ac.ir" target="_blank">http://hashemifar.iut.ac.ir</a><br>

---------------------------------------------------------------------------</div>
<br><br><div class="gmail_quote">On Sat, Jan 26, 2013 at 5:14 AM, Caloma Trumica <span dir="ltr"><<a href="mailto:spmmal@gmail.com" target="_blank">spmmal@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

Dear All,<div><br></div><div>I have a quick question:</div><div><br></div><div>why the HSE-type calculations are much more time consuming than standard DFT calculations.</div><div><br></div><div>Thanks.</div><div><br></div>


<div>Andy</div>
<br>_______________________________________________<br>
Pw_forum mailing list<br>
<a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>
<a href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a><br></blockquote></div><br>