Dear ALPS users,<br>I have two questions regarding  DMRG application of ALPS;<br>1. is it possible to define imaginary operators in this new version? in the simplest case  I tried for operator like Sy=1/(2*I)(S+-S-) and it seems doesn&#39;t recognise I, how should i define the imaginary part?<br clear="all">
2. I am interested to calculate correlations like &lt;O1O2O3&gt; in which O&#39;s are local operators and they could be also imaginary like Sy  in (&lt;Sx(i)Sy(j)Sz(k)&gt;?<br>I know at the moment just correlations like &lt;O1O2&gt; are calculable, but I would like to know is it easy to implement the above mentioned problem or is there a kind of trick to do it?<br>
<br>-- <br><div style="text-align:left"><font color="#888888">Sincerely yours,</font><br><font color="#888888">Zhian.</font><br></div><br>