import numpy as np
from vayesta.core.fragmentation.fragmentation import Fragmentation
from vayesta.core.fragmentation.ufragmentation import Fragmentation_UHF
[docs]class SAO_Fragmentation(Fragmentation):
name = "SAO"
[docs] def get_coeff(self):
ovlp = self.get_ovlp()
idt = np.eye(self.nao)
if np.allclose(ovlp, idt):
return idt
x, e_min = self.symmetric_orth(idt, ovlp)
self.log.debugv(
"Lowdin orthogonalization of AOs: n(in)= %3d -> n(out)= %3d , e(min)= %.3e", x.shape[0], x.shape[1], e_min
)
if e_min < 1e-10:
self.log.warning("Small eigenvalue in Lowdin orthogonalization: %.3e !", e_min)
self.check_orthonormal(x)
return x
[docs] def get_labels(self):
return self.mol.ao_labels(None)
[docs] def search_labels(self, labels):
return self.mol.search_ao_label(labels)
[docs]class SAO_Fragmentation_UHF(Fragmentation_UHF, SAO_Fragmentation):
[docs] def get_coeff(self):
x = super().get_coeff()
return (x, x)