<div dir="ltr"><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">Hi,</p><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">I want to calculate the magnitude of k point(in Brillouin zone) of graphene which has a hexagonal unit cell. The lattice parameters of graphene are given below:</p><pre class="gmail-lang-py gmail-s-code-block" style="margin-top:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit;width:auto;max-height:600px;overflow:auto;color:rgb(12,13,14)"><code class="gmail-hljs gmail-language-python" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit;background-color:transparent;white-space:inherit"> &CONTROL
     calculation = <span class="gmail-hljs-string" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">'scf'</span>
     /
     &SYSTEM
                 ibrav = <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">4</span>
                     a = <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">2.46639</span>
                     c = <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">18</span>
    ATOMIC_SPECIES
    C <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">12.0107</span> C.upf
    ATOMIC_POSITIONS (crystal)
    C  <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.333333333</span>  <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.666666666</span>  <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.000000000</span>
    C  <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.666666666</span>  <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.333333333</span>  <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.000000000</span>
    K_POINTS (automatic)
    <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">35</span> <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">35</span> <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">1</span> <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0</span> <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0</span> <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0</span>
</code></pre><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">ibrav 4 has the following lattice vectors.</p><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)"><a href="https://i.sstatic.net/jckbH7Fd.png" rel="nofollow noreferrer" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit"><img src="https://i.sstatic.net/jckbH7Fd.png" alt="enter image description here" style="margin: 0px; padding: 0px; border: 0px; font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; line-height: inherit; font-family: inherit; font-optical-sizing: inherit; font-size-adjust: inherit; font-kerning: inherit; font-feature-settings: inherit; font-variation-settings: inherit; vertical-align: bottom; box-sizing: inherit; max-width: 100%;"></a></p><p style="margin:0px 0px 1.1em;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">If I open the scf.out and choose a k point (as follows)</p><pre class="gmail-lang-py gmail-s-code-block" style="margin-top:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit;width:auto;max-height:600px;overflow:auto;color:rgb(12,13,14)"><code class="gmail-hljs gmail-language-python" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;vertical-align:baseline;box-sizing:inherit;background-color:transparent;white-space:inherit">cart. coord. <span class="gmail-hljs-keyword" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">in</span> units 2pi/alat  
k(   <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">44</span>) = (   <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.3000000</span>   <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.5773503</span>   <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.0000000</span>), wk =   <span class="gmail-hljs-number" style="margin:0px;padding:0px;border:0px;font-style:inherit;font-variant:inherit;font-weight:inherit;font-stretch:inherit;line-height:inherit;font-family:inherit;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:13px;vertical-align:baseline;box-sizing:inherit">0.0300000</span>
</code></pre><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">How can I calculate the magnitude of the |k| in the hexagonal reciprocal unit cell? considering that I know the value of (kx, ky, 0). The lattice is a parallelogram so that |k| does NOT simply equal to sqrt(kx^2+ky^2), right?<br><br>Best</p><p style="margin:0px;padding:0px;border:0px;font-variant-numeric:inherit;font-variant-east-asian:inherit;font-variant-alternates:inherit;font-stretch:inherit;line-height:inherit;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI Adjusted","Segoe UI","Liberation Sans",sans-serif;font-size-adjust:inherit;font-kerning:inherit;font-feature-settings:inherit;font-size:15px;vertical-align:baseline;box-sizing:inherit;clear:both;color:rgb(12,13,14)">M J Hasan<br>PhD Student<br>Mechanical Engineering<br>University of Maine</p></div>