<html>
<head>
<meta http-equiv='Content-Type' content='text/html; charset=UTF-8'>
</head>
<body>
<style>
font{
line-height: 1.6;
}
ul,ol{
padding-left: 20px;
list-style-position: inside;
}
</style>
<div style = 'font-family:微软雅黑,Verdana,"Microsoft Yahei",SimSun,sans-serif;font-size:14px; line-height:1.6;'>
<div ></div><div>
<div>
<div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">Dear All,</div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;"><br></div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">When doing a test of graphene by the tetrahedra_opt method, I fount it prints the complete negative frequencies if using the nq (6x6x1), while right for nq (6x6x2) but cost more times. </div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;"><br></div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">So, what's wrong? How to calculate the phonon of 2D materials by tetrahedra_opt method. Should the number of nq3 be larger than 1 for the tetrahedra_opt method? </div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;"><br></div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">Thanks.</div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;"><br></div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">Best regards,</div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;"><br></div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">Yipeng</div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;"><br></div><div style="color: rgb(49, 53, 59); font-family: 微软雅黑, Verdana, 'Microsoft Yahei', SimSun, sans-serif; line-height: 22.4px;">Henan Normal University, Xinxiang China</div><span>
</span>
</div>
<div>
<span>
<br>
</span>
</div>
<div id="ntes-pcmac-signature" style="font-family:'微软雅黑'">
<div style="font-size:14px; padding: 0; margin:0;line-height:14px;"><br></div>
</div>
</div><!--😀-->
</div>
</body>
</html>