  from pyscf import gto, scf, fci

# Task 1: Transform FCI wavefunction with orbital rotation/transformation

# Create two molecules with different atomic configurations
mol1 = gto.M(atom='H 0 0 0; H 0 0 1.1', basis='6-31g')
mol2 = gto.M(atom='H 0 0 0; H 0 0 1.2', basis='6-31g')

# Calculate FCI energies for both molecules
fci1 = fci.FCI(mol1, 4)
fci2 = fci.FCI(mol2, 4)

# Transform FCI wavefunction from mol1 to match mol2
fci1.transform(mol2)

# Compare transformed wavefunction with FCI solver wavefunction
print(fci1.wfnsym == fci2.wfnsym)

# Task 2: Transfer FCI wavefunction from smaller orbital space to larger one

# Create a molecule with a specific atomic configuration
mol = gto.M(atom='H 0 0 0; H 0 0 1.1', basis='6-31g')

# Calculate FCI energy for molecule
fci = fci.FCI(mol, 4)

# Transfer FCI wavefunction to larger orbital space
fci.expand(5)

# Compare expanded wavefunction with FCI solver wavefunction
print(fci.wfnsym == fci.wfnsym)

# Task 3: Transform FCI wavefunction using a different method

# Create two molecules with different atomic configurations
mol1 = gto.M(atom='H 0 0 0; H 0 0 1.1', basis='6-31g')
mol2 = gto.M(atom='H 0 0 0; H 0 0 1.2', basis='6-31g')

# Calculate FCI energies for both molecules
fci1 = fci.FCI(mol1, 4)
fci2 = fci.FCI(mol2, 4)

# Transform FCI wavefunction from mol1 to match mol2 using a different method
fci1.transform(mol2, method='incore')

# Compare transformed wavefunction with FCI solver wavefunction
print(fci1.wfnsym == fci2.wfnsym)