<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">sorry, but this time I do not understand what you mean ...<div>S></div><div><br><div><div>On Apr 30, 2008, at 11:56 AM, lan haiping wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Thank you ,Stefano!<br>I have misinterpreted the meaning of effective mass.<br>When we talk about NFE states, does it mean that such <br>E-K dispersion should be held between 2 symmetry points, like from X-> Gamma ?<br> <br><div class="gmail_quote">On Mon, Apr 28, 2008 at 1:40 AM, Stefano Baroni <<a href="mailto:baroni@sissa.it">baroni@sissa.it</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div style="">The higher the energy, the lower the effect of the pseudopotential, so high-energy states are expected to be more free-electron like than low-lying ones. I am afraid that the very ocncept of "effective mass" is not very meaningful for these states. However, I would expect (although I have never verified) that for high-lying states the derivative of the band energy with respect to the wavenumber be linear with respect to the wavenumber, with the coefficient given by the inverse of the free-electron mass. SB<div> <br><div><div><div></div><div class="Wj3C7c"><div>On Apr 27, 2008, at 8:27 AM, lan haiping wrote:</div><br></div></div><blockquote type="cite"><div><div></div><div class="Wj3C7c">Dear All,<br><br> I am wondering about the nearly free electron states . To identify such states,<br> does it mean that its effective mass is very close to free electron ,And we can identify<br>it from bands' dispersion ? <br> <br> Bests<br>H.P<br clear="all"><br>-- <br>Hai-Ping Lan <br>Department of Electronics ,<br> Peking University , Bejing, 100871<br></div></div><a href="mailto:lanhaiping@gmail.com" target="_blank">lanhaiping@gmail.com</a>, <a href="mailto:hplan@pku.edu.cn" target="_blank">hplan@pku.edu.cn</a> _______________________________________________<br> Pw_forum mailing list<br><a href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a><br><a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br> </blockquote></div><br></div><br><br><div> <span style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><div style=""> <span style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><div style=""> <span style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"><div style=""> <div><div style="margin: 0px;"><font size="3"><span style="font-size: 12px;">---</span></font></div><div style="margin: 0px;"><font size="3"><span style="font-size: 12px;">Stefano Baroni - SISSA</span></font><font size="3"><span style="font-size: 12px;"> </span></font><font size="3"><span style="font-size: 12px;">&</span></font><font size="3"><span style="font-size: 12px;"> </span></font><font size="3"><span style="font-size: 12px;">DEMOCRITOS National Simulation Center - Trieste</span></font></div> <div style="margin: 0px;"><font size="3"><span style="font-size: 12px;">[+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype)</span></font></div><div style="margin: 0px; min-height: 14px; font-size: 12px;"><br style="font-size: 12px;"> </div><div style="margin: 0px; min-height: 14px; font-size: 12px;"><span style="font-size: 14px;"><div style="margin: 0px;"><font size="3"><span style="font-size: 12px;">La morale est une logique de l'action comme la logique est une morale de la pensée - Jean Piaget</span></font></div> <div style="margin: 0px;"><font size="3"><span style="font-size: 12px;"><br></span></font></div></span></div><div style="margin: 0px;"><font size="3"><span style="font-size: 12px;">Please, if possible, don't</span></font><font size="3"><span style="font-size: 12px;"> </span></font><font size="3"><span style="font-size: 12px;">send me MS Word or PowerPoint attachments</span></font></div> <div style="margin: 0px;"><font size="3"><span style="font-size: 12px;">Why? See:</span></font><font size="3"><span style="font-size: 12px;"> </span></font><font color="#0023e9" size="3"><span style="font-size: 12px;"><a href="http://www.gnu.org/philosophy/no-word-attachments.html" target="_blank">http://www.gnu.org/philosophy/no-word-attachments.html</a></span></font></div> <div><font color="#0023e9" size="3"><span style="font-size: 12px;"><br></span></font></div></div></div></span><br></div></span><br></div></span><br> </div><br></div><br>_______________________________________________<br> Pw_forum mailing list<br> <a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br> <a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br> <br></blockquote></div><br><br clear="all"><br>-- <br>Hai-Ping Lan <br>Department of Electronics ,<br>Peking University , Bejing, 100871<br><a href="mailto:lanhaiping@gmail.com">lanhaiping@gmail.com</a>, <a href="mailto:hplan@pku.edu.cn">hplan@pku.edu.cn</a> _______________________________________________<br>Pw_forum mailing list<br><a href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>http://www.democritos.it/mailman/listinfo/pw_forum<br></blockquote></div><br><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">---</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Stefano Baroni - SISSA</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">&</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">DEMOCRITOS National Simulation Center - Trieste</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">[+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype)</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; min-height: 14px; font-size: 12px; "><br style="font-size: 12px; "></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; min-height: 14px; font-size: 12px; "><span class="Apple-style-span" style="font-size: 14px; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">La morale est une logique de l'action comme la logique est une morale de la pensée - Jean Piaget</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "><br></span></font></div></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Please, if possible, don't</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">send me MS Word or PowerPoint attachments</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Why? See:</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" color="#0023E9" size="3"><span class="Apple-style-span" style="font-size: 12px; "><a href="http://www.gnu.org/philosophy/no-word-attachments.html">http://www.gnu.org/philosophy/no-word-attachments.html</a></span></font></div><div><font class="Apple-style-span" color="#0023E9" size="3"><span class="Apple-style-span" style="font-size: 12px; "><br class="webkit-block-placeholder"></span></font></div></div></div></span><br class="Apple-interchange-newline"></div></span><br class="Apple-interchange-newline"></div></span><br class="Apple-interchange-newline"> </div><br></div></body></html>