Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

update entanglement forging notebook to use larger active space and brickwork ansatz #72

Merged
merged 1 commit into from
Nov 6, 2023
Merged

update entanglement forging notebook to use larger active space and brickwork ansatz #72

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 16 additions & 10 deletions docs/tutorials/05-entanglement-forging.ipynb
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,6 @@
"import pyscf.mcscf\n",
"import ffsim\n",
"import math\n",
"import numpy as np\n",
"\n",
"# Build a water molecule\n",
"radius_1 = 0.958 # position for the first H atom\n",
Expand All @@ -44,7 +43,7 @@
"hartree_fock.kernel()\n",
"\n",
"# Define active space\n",
"active_space = [1, 2, 4, 5, 6]\n",
"active_space = range(1, mol.nao_nr())\n",
"\n",
"# Get molecular data and molecular Hamiltonian (one- and two-body tensors)\n",
"mol_data = ffsim.MolecularData.from_hartree_fock(\n",
Expand All @@ -68,24 +67,31 @@
"source": [
"import numpy as np\n",
"\n",
"n_reps = 1\n",
"\n",
"# Construct ansatz operator\n",
"interaction_pairs = [(0, 1), (3, 4), (1, 4), (0, 2), (3, 4)]\n",
"thetas = np.zeros(n_reps * len(interaction_pairs))\n",
"def brickwork(norb: int, n_layers: int):\n",
" for i in range(n_layers):\n",
" for j in range(i % 2, norb - 1, 2):\n",
" yield (j, j + 1)\n",
"\n",
"\n",
"n_layers = norb\n",
"interaction_pairs = list(brickwork(norb, n_layers))\n",
"rng = np.random.default_rng(1234)\n",
"thetas = rng.uniform(-np.pi, np.pi, size=len(interaction_pairs))\n",
"operator = ffsim.HopGateAnsatzOperator(interaction_pairs, thetas=thetas)\n",
"\n",
"# Construct ansatz state\n",
"reference_occupations_spatial = [(0, 1, 2), (1, 2, 3), (1, 2, 4)]\n",
"reference_occupations_spatial = [(0, 1, 2, 3), (1, 2, 3, 4), (0, 1, 2, 4)]\n",
"reference_occupations = list(\n",
" zip(reference_occupations_spatial, reference_occupations_spatial)\n",
")\n",
"hamiltonian = ffsim.linear_operator(mol_hamiltonian, norb=norb, nelec=nelec)\n",
"ansatz_state = ffsim.multireference_state(\n",
" hamiltonian, operator, reference_occupations, norb=norb, nelec=nelec\n",
" mol_hamiltonian, operator, reference_occupations, norb=norb, nelec=nelec\n",
")\n",
"\n",
"# Compute the energy ⟨ψ|H|ψ⟩ of the ansatz state\n",
"hamiltonian = ffsim.linear_operator(mol_hamiltonian, norb=norb, nelec=nelec)\n",
"energy = np.real(np.vdot(ansatz_state, hamiltonian @ ansatz_state))\n",
"print(f\"Energy at initialialization: {energy}\")"
]
Expand All @@ -111,7 +117,7 @@
"\n",
"\n",
"result = scipy.optimize.minimize(\n",
" fun, x0=operator.thetas, method=\"COBYLA\", options=dict(maxiter=100)\n",
" fun, x0=operator.thetas, method=\"L-BFGS-B\", options=dict(maxfun=100)\n",
")\n",
"\n",
"print(f\"Number of parameters: {len(result.x)}\")\n",
Expand All @@ -135,7 +141,7 @@
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.10.13"
"version": "3.10.12"
},
"orig_nbformat": 4
},
Expand Down