3.7.20. horton.meanfield.utils – Utility functions¶
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horton.meanfield.utils.check_dm(dm, overlap, lf, eps=0.0001, occ_max=1.0)¶ Check if the density matrix has eigenvalues in the proper range.
Arguments:
- dm
- The density matrix
- overlap
- The overlap matrix
- lf
- A LinalgFactory instance.
Optional arguments:
- eps
- The threshold on the eigenvalue inequalities.
- occ_max
- The maximum occupation.
A ValueError is raised when the density matrix has illegal eigenvalues.
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horton.meanfield.utils.get_level_shift(dm, overlap)¶ Construct a level shift operator.
Arguments:
- dm
- A density matrix.
- overlap
- The overlap matrix
Returns: The level-shift operator.
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horton.meanfield.utils.get_spin(exp_alpha, exp_beta, overlap)¶ Returns the expectation values of the projected and squared spin
Arguments:
- exp_alpha, exp_beta
- The alpha and beta orbitals.
- overlap
- The overlap matrix
Returns: sz, ssq
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horton.meanfield.utils.get_homo_lumo(*exps)¶ Return the HOMO and LUMO energy for the given expansion
Arguments:
- exp1, exp2, …
- DensityExpansion objects
Returns: homo_energy, lumo_energy. (The second is None when all orbitals are occupied.)
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horton.meanfield.utils.compute_commutator(dm, fock, overlap, work, output)¶ Compute the dm-fock commutator, including an overlap matrix
Arguments: (all TwoIndex objects)
- dm
- A density matrix
- fock
- A fock matrix
- overlap
- An overlap matrix
- work
- A temporary matrix
- output
- The output matrix in which the commutator, S.D.F-F.D.S, is stored.