On Fri, Jul 13, 2012 at 2:25 PM,  <span dir="ltr">&lt;<a href="mailto:fn1@rice.edu" target="_blank">fn1@rice.edu</a>&gt;</span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

I am wondering why f/sigf is always about twice of i/sigi. Is there any mathematics behind this relation? Maybe it is not directly related to phenix, but i sincerely hope someone could help me with it.<br></blockquote><div>

<br></div><div>I don&#39;t know the logic behind this, but from notes in our code, the default implementation appears to be this one:</div><div><br></div><div><a href="http://www.iucr.org/__data/iucr/cif/software/xtal/xtal372htmlman/html/addref-desc.html">http://www.iucr.org/__data/iucr/cif/software/xtal/xtal372htmlman/html/addref-desc.html</a> </div>

<div><br></div><div>specifically, section 4.5.2.4.</div><div><br></div><div>-Nat</div><h3 class="SECT3" style="font-family:&#39;Gill Sans&#39;;font-size:medium"><div class="SECT2" style="font-weight:normal"></div></h3></div>