Dear All, I would like to attempt the analytic continuation of greens function produced by TRIQS to obtain the spectral function. I have installed the maxent tool, but can not find how to use it. Can anyone show me some example input files and other information on its functioning? A reference on the method would also be useful. Thanks, David Tompsett.
Hi David, the maxent tool is unfortunately undocumented. You can find a very simple sample parameter file for the most common case in the 'hybdoc.pdf' file in alps/doc as figure 1 (p. 13). Here is a copy of it: N_ALPHA = 60 //the number of alphas between alpha min and max ALPHA_MIN = 0.05 //smallest alpha value to be evaluated ALPHA_MAX = 5 //largest alpha value to be evaluated NORM = 1.0 //normalization of the function to be continued OMEGA_MAX = 25 //frequency range, symmetric by default. specify omega_min otherwise KERNEL = fermionic //Maxent kernel BETA = 60.0 //inverse temperature NFREQ = 2001 //number of output frequencies NDAT = 512 //number of input data points FREQUENCY_GRID = Lorentzian //frequency grid, e.g. Lorentzian, Linear, ... DATASPACE =frequency //dataspace, e.g. imag time or frequency MAX_IT = 2000 //number of iterations for iterative minimization procedure DEFAULT_MODEL = "flat" { PARTICLE_HOLE_SYMMETRY = 1 //either the model is particle hole symmetric or not X_0 = -1.58151510066 //data point X_0, here the lowest frequency point X_1 = -1.19058822793 ...etc... X_511 = -0.0186270492461 SIGMA_0 = 0.00526104728966 //errors of X_0 SIGMA_1 = 0.00199036770537 ...etc... SIGMA_511 = 3.42643209543e-07 } Good luck! Emanuel On Dec 10, 2012, at 2:08 AM, dt331@bath.ac.uk wrote:
Dear All,
I would like to attempt the analytic continuation of greens function produced by TRIQS to obtain the spectral function. I have installed the maxent tool, but can not find how to use it. Can anyone show me some example input files and other information on its functioning? A reference on the method would also be useful.
Thanks, David Tompsett.
Dear Emmanuel, Thanks for the response, but I could not find any file called 'hybdoc.pdf' in the alps-2.1.1-r6176-src.tar.gz tree. Am I looking in the right place? Thanks, David. -- Dr. David A. Tompsett Materials Chemistry Group Department of Chemistry University of Bath Bath BA2 7AY U.K. Tel: +44 7907 566351 (mobile) Fax: +44 1225 386231 http://people.bath.ac.uk/msi20/
participants (3)
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David Tompsett
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dt331@bath.ac.uk
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Emanuel Gull