Dear Sir, Thanks for your prompt response. Yes, I did try I. The program for calculating the ground-state energy works as it did, without taking into account the new term (containing I) which I added in the models.xml file. I defined an Sy operator just like Sx. But Sy contains a sqrt(-1). The message I got was "Sy cannot be evaluated". With regards, Pradeep Thakur On 28 September 2013 17:13, Matthias Troyer <troyer@phys.ethz.ch> wrote:
Have you tried I ?
On Sep 28, 2013, at 1:43 PM, pradeep thakur <pskvkthakur@gmail.com> wrote:
Dear All,
How can I introduce "i" (square-root of -1) into the model library (models.xml file)? I'm unable to define new site- and bond-operators which involve "i".
Any help will be very much appreciated.
With regards, Pradeep Thakur Dept. of Physics., University of Pune, Pune, Maharashtra, INDIA.