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<div name="messageBodySection" style="font-size: 14px; font-family: -apple-system, BlinkMacSystemFont, sans-serif;">Dear all,
<div>when representing the plane wave expansion of the KS orbital several conventions are found in the literature. Just wondering which one of the following is the one used in QE?</div>
<div><br /></div>
<div><b>1)</b></div>
<div>psi(r) = \sum C(G) e^{i G r)</div>
<div>C(G) = 1/Omega \sum psi(r) e^(-i Gr)</div>
<div><b>2) </b></div>
<div>
<div>psi(r) = 1/sqrt(Omega) \sum C(G) e^{i G r)</div>
<div>C(G) = 1/sqrt(Omega) \sum psi(r) e^(-i Gr)</div>
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<div><br /></div>
<div>
<div><b>3)</b> </div>
<div>
<div>psi(r) = 1/Omega \sum C(G) e^{i G r)</div>
<div>C(G) = \sum psi(r) e^(-i Gr)</div>
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<div><br /></div>
<div>I have omitted the k dependence for brevity reasons</div>
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<div>Best regards,</div>
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<div name="messageSignatureSection" style="font-size: 14px; font-family: -apple-system, BlinkMacSystemFont, sans-serif;"><br />
<span style="orphans: 2; widows: 2;">Lic. Miguel Carvajal - Instituto Balseiro - Bariloche</span>
<pre style="font-variant-ligatures: normal; orphans: 2; widows: 2;">[+54] 2944782429 (tel) / krvajal.miguel (skype)</pre>
<pre style="font-variant-ligatures: normal; orphans: 2; widows: 2;">LinkedIn: <a href="https://www.linkedin.com/in/krvajal/">in/krvajal</a><br /></pre></div>
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