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I think, after creating an index file, you can edit it manually clubbing both Phosphorius and Oxygen atoms together ( considering as a single group). Then specify this group while doing analysis.<BR>
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On Wed, 16 Jul 2008 minnale wrote :<BR>
> Thanks for the reply, may be this is trivial question to you<BR>
>That I know that how to select phosrous atom alone of POPC.<BR>
>Normally people are using only phosphrous atom or PO4 group ? for density calculation ,etc analysis. In one article I found that they have done density analysis for PO4 group.<BR>
>Could you please tell me which one use it for analysis if PO4 how select by using make_ndx?<BR>
>Thanks alot in advance.<BR>
><BR>
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