quemb.kbe.solver.schmidt_decomp_svd

quemb.kbe.solver.schmidt_decomp_svd(rdm, Frag_sites, thr_bath=1e-10)

Perform decomposition on the orbital coefficients in the real space.

This function decomposes the molecular orbitals into fragment and environment parts using the Schmidt decomposition method. It computes the transformation matrix (TA) which includes both the fragment orbitals and the entangled bath.

Parameters:

  • rdm (ndarray) – Density matrix (HF) in the real space.

  • Frag_sites (list of int) – List of fragment sites (indices).

  • thr_bath (float,) – Threshold for bath orbitals in Schmidt decomposition

Returns:

Transformation matrix (TA) including both fragment and entangled bath orbitals.

Return type:

ndarray