Post-processing

The Green provides several post-processing procedures such as analytical continuation packages to obtain spectral representations and thermodynamic utilities to obtain thermodynamic quantities.

Spectral representation

To obtain the spectral representation of a Green’s function, the Green software stack provides an analytical continuation package.

To run the analytical continuation one have to execute the program ac.exe located at the installation path in the bin subdirectory. The following parameters are required:

• --grid_file Sparse imaginary time/frequency grid file name
• --BETA Inverse temperature
• --input_file Name of the input file
• --output_file Name of the output file
• --group Name of the HDF5 group in the input file, that contains imaginary time data, it has to contain mesh and data datasets.
• --kind Type of analytical continuation, currently only NEVANLINNA is implemented.

The command ac.exe --help will provide additional information.