Hello,
The input parameters I gave were: _____________________________ parms = [] for D in [80]: parms.append( { 'LATTICE' : 'open chain lattice', 'MODEL' : 'spin', 'CONSERVED_QUANTUMNUMBERS' : 'N,Sz', # 'Sz_total' : 0, 'COMPLEX' : 1, 'Jz' : 4.5, 'Jxy' : 1.0, # 'E' : 1.0, 'SWEEPS' : 8, 'NUMBER_EIGENVALUES' : 1, 'L' : 32, 'MAXSTATES' : D, 'MEASURE_CORRELATIONS[Sx_Sy]' : 'Sx:Sy', 'MEASURE_CORRELATIONS[Sy_Sx]' : 'Sy:Sx', } ) _____________________________
I defined Sy in the models.xml file as: <SITEOPERATOR name="Sy" site="x"> -(I/2)*(Splus(x)-Sminus(x)) </SITEOPERATOR> _____________________________
Sx has already been defined. The parameter E is the coefficient of an extra term in the Hamiltonian which I have introduced for studying my problem of interest. I have set the default value of E to be 0, so that the entire new term is excluded from the current calculation.
rgrds, Pradeep Thakur
On 30 September 2013 16:49, German Sinuco gsinuco@gmail.com wrote:
Hi there,
Apologize for the naive question, where the parameter COMPLEX should be set? I cannot see it in CMakeCache.txt.
Regards,
German Sinuco
On Sun, Sep 29, 2013 at 2:53 PM, Matthias Troyer troyer@phys.ethz.chwrote:
It will help me explore this issue if you send your input files.
Matthias Troyer
On Sep 28, 2013, at 2:49 PM, pradeep thakur pskvkthakur@gmail.com wrote:
Thank you for your time.
With regards, Pradeep Thakur.
On 28 September 2013 18:11, Matthias Troyer troyer@phys.ethz.ch wrote:
We will look into that next week.
Thank you for reporting the problem
Matthias Troyer
On Sep 28, 2013, at 14:33, pradeep thakur pskvkthakur@gmail.com wrote:
I had not tried it before. But I tried it just now and still, I get the same msg: "Cannot evaluate expression Sy(i)".
On 28 September 2013 17:58, Matthias Troyer troyer@phys.ethz.ch wrote:
Did you set the parameter COMPLEX to 1, so that it actually runs a complex version?
On Sep 28, 2013, at 2:26 PM, pradeep thakur pskvkthakur@gmail.com wrote:
Yes, I didn't use sqrt(-1); I simply used I.
I have been using the 4 DMRG codes.
The code which calculates the ground-state energy ran, but yielded results which didn't account for the additional term which had an "I" in it.
In the code for calculating correlations, I tried to calculate Sx:Sy. I defined Sy in the models.xml file as:
<SITEOPERATOR name="Sy" site="x"> -(I/2)*(Splus(x)-Sminus(x)) </SITEOPERATOR>
The program doesn't run and I get the message: "Cannot evaluate expression Sy(i)".
On 28 September 2013 17:32, Matthias Troyer troyer@phys.ethz.chwrote:
What code are you running?
sqrt(-1) will not work, by the way
On Sep 28, 2013, at 1:56 PM, pradeep thakur pskvkthakur@gmail.com wrote:
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.chwrote:
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.
-- Dr. German Sinuco School of Physics and Astronomy University of Sussex Brighton - UK Tel: +44 (0) 1273 678187