Tequila Version 1.9.5

• orbital names are better tracked through transformations (#338)
• keep basis info when re-initializing with mol.from_tequila

Example (Gaussian Basis Set)

needs

pip install pyscf

geom = "H 0.0 0.0 0.0\nH 0.0 0.0 1.5"
mol = tq.Molecule(geometry=geom, basis_set="sto-3g")

mol.print_basis_info()

gives

basis_name       : sto-3g
orbital_type     : hf
orthogonal basis : False
basis functions  : 2
active orbitals  : [0, 1]
reference        : [0]
Current Orbitals
{idx_total:0, idx:0}
coefficients:  [0.63074567 0.63074567]
{idx_total:1, idx:1}
coefficients:  [ 0.82021585 -0.82021585]

change to "native orbitals", meaning in this case orthonormalized atomics

mol = mol.use_native_orbitals()
mol.print_basis_info()

gives

basis_name       : sto-3g
orbital_type     : orthonormalized-sto-3g-basis
orthogonal basis : False
basis functions  : 2
active orbitals  : [0, 1]
reference        : [0]
Current Orbitals
{idx_total:0, idx:0}
coefficients:  [ 1.02598473 -0.13397565]
{idx_total:1, idx:1}
coefficients:  [-0.13397565  1.02598473]

Using the orbital optimization routine will now set the orbital coefficients w.r.t the original basis

U = mol.make_ansatz(name="SPA", edges=[(0,1)])
opt = tq.chemistry.optimize_orbitals(molecule=mol, circuit=U)
mol2 = opt.molecule
mol2.print_basis_info()

basis_name       : sto-3g
orbital_type     : optimized
orthogonal basis : False
basis functions  : 2
active orbitals  : [0, 1]
reference        : [0]
Current Orbitals
{idx_total:0, idx:0}
coefficients:  [-0.63074597 -0.63074537]
{idx_total:1, idx:1}
coefficients:  [ 0.82021562 -0.82021608]

Example MRA-PNOs

MRA-PNOs from the madness module, need

pip install pyscf
conda install madtequila -c kottmann

geom = "H 0.0 0.0 0.0\nH 0.0 0.0 1.5"
mol = tq.Molecule(geometry=geom)

mol.print_basis_info()

basis_name       : mra
orbital_type     : pno
orthogonal basis : True
basis functions  : 2
active orbitals  : [0, 1]
reference        : [0]
Current Orbitals
{idx_total:0, idx:0, occ:2.0, pair:(0, 0)}
coefficients:  [1. 0.]
{idx_total:1, idx:1, occ:0.0425791, pair:(0, 0)}
coefficients:  [0. 1.]

MRA-PNOs are the native basis, so mol.use_native_basis() has no effect here. After calling the orbital-optimizer, coefficients of the optimized molecule are w.r.t the MRA-PNOs.

• fixing syntax issue in post_init of dataclass (#327)

• Support for phoenics optimizer dropped (dependency not maintained anymore and problems with downstream dependencies are piling up)

• more convenient randomization initialization for orbital optimizer (e.g initial_guess="near_zero" )

• Update qasm.py (#334, #335) Fixes issue #332

• added methods to create annihilation, creation, sz, sp, sm and s2 operators in qubit representation (#336)

ak = mol.make_annihilation_op(k) # spin-orbital k
ck = mol.make_creation_op(k)
ck = ak.dagger()
S = mol.make_s2_op() # total-spin operator
Sz = mol.make_sz_op() # spin-polarization
Nk = mol.make_number_op(k)

Co-authored-by: davibinco 59845652+davibinco@users.noreply.github.com