<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
Dear Vahid,
<div class="">I didn’t give a detailed thought to your system, but I give just a general suggestion: if you have two p-orbitals making a covalent bond, and you are looking at valence bands, a good starting point would be s-like projections mid-bond, where the
bonding orbital would be peaked.</div>
<div class=""><br class="">
</div>
<div class="">So I would try with mid-bond s orbitals (you have though to do some counting to see if this gives you the right number of projections).</div>
<div class=""><br class="">
</div>
<div class="">Hope this helps,</div>
<div class="">Giovanni Pizzi</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
<div class="">
<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;">
-- <br class="">
Giovanni Pizzi<br class="">
Theory and Simulation of Materials and MARVEL, EPFL<br class="">
<a href="http://people.epfl.ch/giovanni.pizzi" class="">http://people.epfl.ch/giovanni.pizzi</a><br class="">
http://nccr-marvel.ch/en/people/profile/giovanni-pizzi</div>
</div>
<br class="">
<div>
<blockquote type="cite" class="">
<div class="">On 18 May 2018, at 01:56, Vahid Askarpour <<a href="mailto:vh261281@dal.ca" class="">vh261281@dal.ca</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<div class="">Dear Wannier Community,<br class="">
<br class="">
I am attempting to generate the Wannier functions for the valence states of Mg3As2 (semiconductor). The 8 valence states consist of Mg s-states and As s and p states. Mg atoms have 2 electrons and As atoms have 5 for a total of 16 electrons.<br class="">
<br class="">
The 3 Mg atoms are not equivalent. Two Mg atoms form covalent bonds with the two As atoms. The third Mg atom donates two electrons to complete the covalent bonding. So the bonding is a mixture of ionic and covalent, i.e., [Mg](+2)[Mg2As2](-2) with Mg2As2 being
covalently bonded.<br class="">
<br class="">
To generate 8 Wannier functions, I define As:s and Mg:s and get 5 states. The other 3 states have to come from As p-states. If I set As:px,py,pz then I get 6 extra states instead of 3. I could define As1:px and As2:py,pz but the As atoms are equivalent and
so should be their projections I assume.<br class="">
<br class="">
My question is how do I define three projections for the half-filled p states of the two As atoms? Or is there another way to look at this system?<br class="">
<br class="">
I would appreciate any suggestions you might have.<br class="">
<br class="">
Thank you,<br class="">
<br class="">
Vahid<br class="">
<br class="">
Vahid Askarpour<br class="">
Department of Physics and Atmospheric Science<br class="">
Dalhousie University,<br class="">
Halifax, NS, Canada<br class="">
_______________________________________________<br class="">
Wannier mailing list<br class="">
<a href="mailto:Wannier@lists.quantum-espresso.org" class="">Wannier@lists.quantum-espresso.org</a><br class="">
https://lists.quantum-espresso.org/mailman/listinfo/wannier<br class="">
</div>
</div>
</blockquote>
</div>
<br class="">
</div>
</body>
</html>