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<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0pt 0pt 0pt 0.8ex; BORDER-LEFT: rgb(204,204,204) 1px solid"><br><br>---------- Пересланное письмо ---------- <br>From: David van der Spoel <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:spoel@xray.bmc.uu.se" target="_blank">
spoel@xray.bmc.uu.se</a>><br>To: Discussion list for GROMACS users <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:gmx-users@gromacs.org" target="_blank">gmx-users@gromacs.org</a>><br>Date: Fri, 26 Jan 2007 10:02:01 +0100
<br>Subject: Re: [gmx-users] g_gyrate<br>Dmitriy Golubobsky wrote:<br>> Dear Gurus,<br>> I've got question on Radius of gyrtion calculation.<br>> my system consists of 1 polymer and a solvent.<br>> I did MD and decide to calculate Rg for this system
<br>> I made index group consisting my residues<br>> g_gyrate -f xtc_file -s tpr_file -n ndx_file -p -o xvg_output<br>> ok. I've got the output file with 4 colums: time Rg Rx Ry Rz<br>> I use -p option to get components in principal axes, because I' d like
<br>> to calculate form-factors for my system.<br>><br>> as I undersand Rg = sqrt ( sum_{i}^{N} r_i*m_i)/M)<br>> ok. then fx=Rx/Rg^2, fy=Ry/Rg^2, fz=Rz/Rg^2<br>> and I wish to get fx+fy+fz=1 but it is not so.
<br>> where I'm mistaken?<br>> How does components Rxyz in principal axes are calculated?<br>> I'm using gromacs 3.3.1<br>> Thanks a lot.<br>Rg = sqrt ( sum_{i}^{N} (r_i^2)*m_i)/M)</blockquote></div></blockquote>
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<div>This question can be asked on momet of inertia too.</div>
<div>if I'm calculating moment of ineria in pricipal axes.</div>
<div>is it possible to diagonialize tenzor of inertia? and to get it components?</div><br> </div>