Set up two different domains

Contents

# Force the local gqcpy to be imported
import sys
sys.path.insert(0, '../../build/gqcpy/')

import gqcpy
import numpy as np

Set up two different domains#

Hubbard_domain_1 = gqcpy.HubbardDomain([0, 1, 2], 3)
Hubbard_domain_2 = gqcpy.HubbardDomain([2, 3, 4], 3)

Check some properties between the two domains#

Hubbard_domain_1.overlapWith(Hubbard_domain_2)

Hubbard_domain_1.domainIndices()

[0, 1, 2]

Hubbard_domain_1.inDomain(3)

False

Projection#

We can construct a projection matrix of the domains. We can choose between restricted and unrestricted (R/U). We need to pass the number of sites of the Hubbard system.

P_restricted = Hubbard_domain_1.RProjectionMatrix(5)

By constructing the Hubbard overlap matrix (unit matrix) we can partition it to create a domain operator.

S = gqcpy.ScalarRSQOneElectronOperator_d(np.eye(5))
operator = S.partitioned(P_restricted)

print(operator.parameters())

[[1. 0. 0. 0. 0.]
 [0. 1. 0. 0. 0.]
 [0. 0. 1. 0. 0.]
 [0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0.]]

P_unrestricted = Hubbard_domain_1.UProjectionMatrix(5)

US = gqcpy.ScalarUSQOneElectronOperator_d(gqcpy.ScalarUSQOneElectronOperatorComponent_d(np.eye(5)), gqcpy.ScalarUSQOneElectronOperatorComponent_d(np.eye(5)))
unrestricted_operator = US.partitioned(P_unrestricted)

print(unrestricted_operator.alpha.parameters())

[[1. 0. 0. 0. 0.]
 [0. 1. 0. 0. 0.]
 [0. 0. 1. 0. 0.]
 [0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0.]]

print(unrestricted_operator.beta.parameters())

[[1. 0. 0. 0. 0.]
 [0. 1. 0. 0. 0.]
 [0. 0. 1. 0. 0.]
 [0. 0. 0. 0. 0.]
 [0. 0. 0. 0. 0.]]