johanjoensson / rspt2spectra / 28928084449

79%

push

github

Add the fitted constant hybridization offset to the impurity level

The bath fit models Delta_fit(z) = Delta_pole(z) + C, where the
discrete poles carry no constant part. Matching RSPt's Weiss field
g0^-1 = z - H_imp - Delta(z) with the discretized model
G0^-1 = z - E_imp - Delta_pole(z) therefore requires
E_imp = H_imp + C: the constant hybridization content the poles cannot
carry moves into the impurity level. The previous code subtracted C
(treating it as static content already present in the local
Hamiltonian), which displaced the impurity level by 2C; RSPt's ham
does not contain Delta's static part (hybridization_function in
green_solver.F90 subtracts ham exactly once from the Weiss field).

assemble_h0 now adds the shift to the impurity block and the chain
anchor, and build_h0 folds the fitted C into its filter shift with the
opposite sign (the filter shift is already minus the dropped poles'
constant contribution). Tests updated to pin the new sign.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

3 of 3 new or added lines in 2 files covered. (100.0%)

1602 of 1871 relevant lines covered (85.62%)

3.42 hits per line