vayesta.core.screening
Submodules
vayesta.core.screening.screening_crpa
- exception vayesta.core.screening.screening_crpa.cRPAError[source]
Bases:
RuntimeError- args
- with_traceback()
Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.
- vayesta.core.screening.screening_crpa.get_frag_W(mf, fragment, pcoupling=True, only_ov_screened=False, log=None)[source]
Generates screened coulomb interaction due to screening at the level of cRPA. Note that this currently scales as O(N_frag N^6), so is not practical without further refinement.
- Parameters:
mf (pyscf.scf object) – Mean-field instance.
fragment (vayesta.qemb.Fragment subclass) – Fragments for the calculation, used to define local interaction space.
log (logging.Logger, optional) – Logger object. If None, the logger of the emb object is used. Default: None.
- Returns:
freqs (np.array) – Effective bosonic frequencies for cRPA screening.
couplings (np.array) – Effective bosonic couplings for cRPA screening.
- vayesta.core.screening.screening_crpa.get_frag_deltaW(mf, fragment, pcoupling=True, only_ov_screened=False, log=None)[source]
Generates change in coulomb interaction due to screening at the level of static limit of cRPA. Note that this currently scales as O(N_frag N^6), so is not practical without further refinement.
- Parameters:
mf (pyscf.scf object) – Mean-field instance.
fragment (vayesta.qemb.Fragment subclass) – Fragments for the calculation, used to define local interaction space.
log (logging.Logger, optional) – Logger object. If None, the logger of the emb object is used. Default: None.
- Returns:
deltaW – Change in cluster local coulomb interaction due to cRPA screening.
- Return type:
np.array
vayesta.core.screening.screening_moment
- vayesta.core.screening.screening_moment.build_screened_eris(emb, fragments=None, cderi_ov=None, store_m0=True, npoints=48, log=None)[source]
Generates renormalised coulomb interactions for use in local cluster calculations. Currently requires unrestricted system.
- Parameters:
emb (Embedding) – Embedding instance.
fragments (list of vayesta.qemb.Fragment subclasses, optional) – List of fragments for the calculation, used to define local interaction spaces. If None, emb.get_fragments(sym_parent=None) is used. Default: None.
cderi_ov (np.array or tuple of np.array, optional.) – Cholesky-decomposed ERIs in the particle-hole basis of mf. If mf is unrestricted this should be a list of arrays corresponding to the different spin channels.
store_m0 (bool, optional.) – Whether to store the local zeroth moment in the fragment class for use later.
npoints (int, optional) – Number of points for numerical integration. Default: 48.
log (logging.Logger, optional) – Logger object. If None, the logger of the emb object is used. Default: None.
- Returns:
seris_ov (list of tuples of np.array) – List of spin-dependent screened (ov|ov), for each fragment provided.
erpa (float) – Delta RPA correction computed as difference between full system RPA energy and cluster correlation energies; currently only functional in CAS fragmentations.
- vayesta.core.screening.screening_moment.calc_moms_RIRPA(mf, target_rots, ovs_active, log, cderi_ov, npoints)[source]
- vayesta.core.screening.screening_moment.calc_moms_RPA(mf, target_rots, ovs_active, log, cderi_ov, npoints)[source]