<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title></title>
<META http-equiv=Content-Type content="text/html; charset=utf-8">
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
body {
margin: 5px 5px 5px 5px;
background-color: #ffffff;
}
/* ========== Text Styles ========== */
hr { color: #000000}
body, table /* Normal text */
{
font-size: 9pt;
font-family: 'Courier New';
font-style: normal;
font-weight: normal;
color: #000000;
text-decoration: none;
}
span.rvts1 /* Heading */
{
font-size: 10pt;
font-family: 'Arial';
font-weight: bold;
color: #0000ff;
}
span.rvts2 /* Subheading */
{
font-size: 10pt;
font-family: 'Arial';
font-weight: bold;
color: #000080;
}
span.rvts3 /* Keywords */
{
font-size: 10pt;
font-family: 'Arial';
font-style: italic;
color: #800000;
}
a.rvts4, span.rvts4 /* Jump 1 */
{
font-size: 10pt;
font-family: 'Arial';
color: #008000;
text-decoration: underline;
}
a.rvts5, span.rvts5 /* Jump 2 */
{
font-size: 10pt;
font-family: 'Arial';
color: #008000;
text-decoration: underline;
}
span.rvts6
{
font-size: 11pt;
font-weight: bold;
color: #ffffff;
background-color: #0000ff;
}
span.rvts7
{
font-size: 10pt;
}
span.rvts8
{
font-size: 10pt;
color: #444444;
}
a.rvts9, span.rvts9
{
font-size: 10pt;
color: #999999;
text-decoration: underline;
}
a.rvts10, span.rvts10
{
font-size: 10pt;
color: #444444;
text-decoration: underline;
}
span.rvts11
{
font-size: 8pt;
font-family: 'arial';
font-style: italic;
color: #c0c0c0;
}
a.rvts12, span.rvts12
{
font-size: 8pt;
font-family: 'arial';
color: #0000ff;
text-decoration: underline;
}
a.rvts13, span.rvts13
{
color: #0000ff;
text-decoration: underline;
}
/* ========== Para Styles ========== */
p,ul,ol /* Paragraph Style */
{
text-align: left;
text-indent: 0px;
padding: 0px 0px 0px 0px;
margin: 0px 0px 0px 0px;
}
.rvps1 /* Centered */
{
text-align: center;
}
--></style>
</head>
<body>
<p>Dear Huang.</p>
<p><br></p>
<p>Thank you for the answer!</p>
<p><br></p>
<p>There is a lot of references e.g. <a class=rvts13 href="http://arxiv.org/PS_cache/arxiv/pdf/0802/0802.0912v1.pdf">http://arxiv.org/PS_cache/arxiv/pdf/0802/0802.0912v1.pdf</a></p>
<p>I tried to evaluate only velocities of linear LA and TA modes. The ZA mode seems have more complicated relationship with velocity.</p>
<p>OK, it seems that I should just multiply my results by 2*pi... But why?</p>
<p><br></p>
<p><br></p>
<p>You wrote at 3/25/2010, 10:04:00 PM</p>
<p><br></p>
<div><a name="SEND_MAIL"></a>
<table border=0 cellpadding=1 cellspacing=2 style="background-color: #ffffff;">
<tr valign=top>
<td width=9 style="background-color: #0000ff;">
<p><span class=rvts6>></span></p>
</td>
<td width=1241>
<p><span class=rvts7>Dear P. B. Sorokin: </span></p>
<p><span class=rvts8>> But when I try to evaluate the velocity I obtain the answer nearly in </span></p>
<p><span class=rvts8>> six time less then reported early: 2200 m/s and 3400 m/s vs. 12200 </span></p>
<p><span class=rvts8>> m/s and 19500 m/s. </span></p>
<p><span class=rvts8>> I do some stupid mistake, but where? Does anybody has the experience </span></p>
<p><span class=rvts8>> in such calculations? </span></p>
<p><span class=rvts8>Where does your reference for the sound velocity come from? And there are 3 acoustic bands for graphene, one of which is the bending mode with a parabolic dispersion near gamma point. Have you pay attention to this band? </span></p>
</td>
</tr>
</table>
</div>
<p><br></p>
<p><span class=rvts11>Sincerely yours,</span></p>
<p><span class=rvts11>Pavel B Sorokin </span><a class=rvts12 href="mailto:PBSorokin@gmail.com">mailto:PBSorokin@gmail.com</a></p>
</body></html>