Qiskit Nature 0.7.1
New Features
- Added the get_overlap_ab_from_qcschema() function which extracts the alpha-beta spin orbital overlap matrix from a QCSchema instance.
Bug Fixes
- Fixes the following operators when dealing with non-orthonormal orbitals (for example when using unrestricted spin orbitals):
- AnglarMomentum
- s_plus_operator()
- s_minus_operator()
- s_x_operator()
- s_y_operator()
To make the fix take effect, the new additional overlap argument needs to be provided to all of these operators.
Prior to this fix, none of the operators above were able to resolve any spin contamination and would yield misleadingly “clean” expectation values. See this issue for a more complete discussion.