Abstract: Techniques facilitating density-functional theory determinations using a quantum computing system are provided. A system can comprise a first computing processor and a second computing processor. The first computing processor can generate a density-functional theory determination. The second computing processor can input a quantum density into the density-functional theory determination. The first computing processor can be operatively coupled to the second computing processor. Further, the first computing processor can be a classical computer and the second computing processor can be a quantum computer.

Abstract: Techniques of facilitating improved computational efficiency in Variational Quantum Eigensolver calculations by quantum computing devices. In one example, a system can comprise a processor that executes computer executable components stored in memory. The computer executable components can comprise: a distribution component; and a feedback component. The distribution component can set a Pauli-dependent sample budget for a Pauli term of an operator to unevenly distribute a total sample budget for evaluating an expected value of the operator among a plurality of Pauli terms composing the operator. The plurality of Pauli terms can comprise the Pauli term. The feedback component can evaluate compatibility between a prescreening variance for the Pauli term and a production variance of the Pauli term generated using the Pauli-dependent sample budget.

Abstract: Systems, computer-implemented methods, and computer program products to facilitate multireference parallelization of variational quantum computing to achieve high accuracy with short circuit depths. According to an embodiment, a system can comprise a processor that executes computer executable components stored in memory. The computer executable components comprise a trial component that prepares a multireference trial state based on a qubit operator, by applying a unitary circuit operator to a sum of selected initial configurations.

Abstract: A method for calculating excited state properties of a molecular system using a hybrid classical-quantum computing system includes determining, using a quantum processor and memory, a ground state wavefunction of a combination of quantum logic gates. In an embodiment, the method includes forming a set of excitation operators. In an embodiment, the method includes forming a set of commutators from the set of excitation operators and a Hamiltonian operator. In an embodiment, the method includes mapping the set of commutators onto a set of qubit states, the set of qubit states corresponding to a set of qubits of the quantum processor. In an embodiment, the method includes evaluating, using the quantum processor and memory, the set of commutators. In an embodiment, the method includes causing a quantum readout circuit to measure an excited state energy from the set of computed commutators.

Abstract: Techniques regarding quantum computation of molecular excited states are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise an initialization component that can categorize a plurality of excited operators from a mapped qubit Hamiltonian into sectors based on a commutation property of the plurality of excited operators with a symmetry from the mapped qubit Hamiltonian. The computer executable components can also comprise a matrix component that can generate an equation of motion matrix from an excited operator from the plurality of excited operators based on the sectors categorized by the initialization component.

Abstract: Systems and methods that facilitate motion formalism utilizing quantum computing, to compute matrix operators in terms of commutators between qubit operators and measurements on the quantum hardware, wherein the commutators are computed utilizing symbolic calculus. Embodiments reduce computational cost of generalized eigenvalue synthesis relying on symbolic calculus and parallelization. Embodiments disclosed herein can also develop estimators of excited-states properties, considering constants of motion (e.g. spin) and non-constants of motions (e.g. dipoles, density matrices).

Abstract: Techniques of facilitating improved computational efficiency in Variational Quantum Eigensolver calculations by quantum computing devices. In one example, a system can comprise a processor that executes computer executable components stored in memory. The computer executable components can comprise: a distribution component; and a feedback component. The distribution component can set a Pauli-dependent sample budget for a Pauli term of an operator to unevenly distribute a total sample budget for evaluating an expected value of the operator among a plurality of Pauli terms composing the operator. The plurality of Pauli terms can comprise the Pauli term. The feedback component can evaluate compatibility between a prescreening variance for the Pauli term and a production variance of the Pauli term generated using the Pauli-dependent sample budget.

Abstract: Systems and methods that facilitate motion formalism utilizing quantum computing, to compute matrix operators in terms of commutators between qubit operators and measurements on the quantum hardware, wherein the commutators are computed utilizing symbolic calculus. Embodiments reduce computational cost of generalized eigenvalue synthesis relying on symbolic calculus and parallelization. Embodiments disclosed herein can also develop estimators of excited-states properties, considering constants of motion (e.g. spin) and non-constants of motions (e.g. dipoles, density matrices).

Abstract: Techniques facilitating density-functional theory determinations using a quantum computing system are provided. A system can comprise a first computing processor and a second computing processor. The first computing processor can generate a density-functional theory determination. The second computing processor can input a quantum density into the density-functional theory determination. The first computing processor can be operatively coupled to the second computing processor. Further, the first computing processor can be a classical computer and the second computing processor can be a quantum computer.

Abstract: A method for calculating excited state properties of a molecular system using a hybrid classical-quantum computing system includes determining, using a quantum processor and memory, a ground state wavefunction of a combination of quantum logic gates. In an embodiment, the method includes forming a set of excitation operators. In an embodiment, the method includes forming a set of commutators from the set of excitation operators and a Hamiltonian operator. In an embodiment, the method includes mapping the set of commutators onto a set of qubit states, the set of qubit states corresponding to a set of qubits of the quantum processor. In an embodiment, the method includes evaluating, using the quantum processor and memory, the set of commutators. In an embodiment, the method includes causing a quantum readout circuit to measure an excited state energy from the set of computed commutators.

Abstract: Techniques regarding quantum computation of molecular excited states are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise an initialization component that can categorize a plurality of excited operators from a mapped qubit Hamiltonian into sectors based on a commutation property of the plurality of excited operators with a symmetry from the mapped qubit Hamiltonian. The computer executable components can also comprise a matrix component that can generate an equation of motion matrix from an excited operator from the plurality of excited operators based on the sectors categorized by the initialization component.