<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>When using MPI, how do I calculate the local atom number from the global one? The code given here<o:p></o:p></p><p class=MsoNormal><a href="http://www.gromacs.org/Developer_Zone/Programming_Guide/Programmer%27s_Guide#local_index">http://www.gromacs.org/Developer_Zone/Programming_Guide/Programmer%27s_Guide#local_index</a><o:p></o:p></p><p class=MsoNormal>does not work for the latest gromacs 4.5.5 which I need. Also, if I understand correctly, the given code only works for domain decomposition. I need a universal method… Thanks!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>My ultimate goal is to hack mdrun such that I can output only a few atoms’ positions and velocities, say atoms 0,1, and 3, but fairly frequently (say, every 10 steps).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Dmitry.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>