<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Hi,<div> I want to run a NPT run,could I put some groups into position restraint, or make them frozened ?</div><div> I find it is OK in NVT ensemble. But I am not sure whether it is proper.</div><div> Thanks!</div><div>Zhongjin He</div></td></tr></table><br>