ueg_sign_problem¶
Script to investigate the sign problem in a UEG system in various bases.
Execute to calculate and print out the lowest eigenvalues of Hamiltonian matrices (and those related to the FCIQMC sign problem) for a small UEG system using the ueg_fci module.
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ueg_sign_problem.
print_title
(title, under='=')¶ Print the underlined title.
Parameters: - title (string) – section title to print out
- under (string) – single character used to underline the title
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ueg_sign_problem.
worker
(label, sys, basis, Hamil, nprint)¶ Helper function to construct and diagonalise matrices related to the sign problem.
Parameters: - label (string) – label of the many-particle basis function used
- sys (
ueg_fci.UEG
) – desired UEG system; passed to Hamil - basis (iterable of iterables of
ueg_fci.BasisFn
) – set of many-particle basis functions - Hamil (
ueg_fci.UEGHamiltonian
subclass) – appropriate Hamiltonian for the basis provided - nprint (integer) – number of eigenvalues to print out