86 citations · 634 across the 31 of their papers we have counts for
31 papers
Multistate iterative qubit coupled cluster (MS-iQCC): a quantum-inspired, state-averaged approach to ground- and excited-state energies
Robert A. Lang, Shashank G. Mehendale, Ilya G. Ryabinkin +1
We introduce the multistate iterative qubit coupled cluster (MS-iQCC) method, a quantum-inspired algorithm that runs efficiently on classical hardware and is designed to predict bo…
Towards Quantum Advantage in Chemistry
Scott N. Genin, Ohyun Kwon, Seyyed Mehdi Hosseini Jenab +7
Molecular simulations are widely regarded as leading candidates to demonstrate quantum advantage--defined as the point at which quantum methods surpass classical approaches in eith…
Open-shell frozen natural orbital approach for quantum eigensolvers
Angela F. Harper, Xiaobing Liu, Scott N. Genin +1
We present an open-shell frozen natural orbital (FNO) approach, which utilizes the second-order Z-averaged perturbation theory (ZAPT2), to reduce the restricted opten-shell Hartree…
Optimization of the Qubit Coupled Cluster Ansatz on classical computers
Ilya G. Ryabinkin, Seyyed Mehdi Hosseini Jenab, Scott N. Genin
Immense interest in quantum computing has prompted development of electronic structure methods that are suitable for quantum hardware. However, the slow pace at which quantum hardw…
Thawed Gaussian wave packet dynamics: a critical assessment of three propagation schemes
Ilya G. Ryabinkin, Rami Gherib, Scott N. Genin
We assessed three schemes for propagating a variable-width (thawed) Gaussian wave packet moving under the influence of Morse or double-well potentials with parameters that are chem…
Thawed Gaussian wavepacket dynamics with -machine learned potentials
Rami Gherib, Ilya G. Ryabinkin, Scott N. Genin
A method for performing variable-width (thawed) Gaussian wavepacket (GWP) variational dynamics on machine-learned potentials is presented. Instead of fitting the potential energy s…
Efficient construction of involutory linear combinations of anti-commuting Pauli generators for large-scale iterative qubit coupled cluster calculations
Ilya G. Ryabinkin, Andrew J. Jena, Scott N. Genin
We present an efficient method for construction of a fully anti-commutative set of Pauli generators (elements of the Pauli group) from a commutative set of operators that are compo…
On the Importance of Well-Defined Thermal Correlation Functions in Simulating Vibronic Spectra
Rami Gherib, Scott N. Genin, Ilya G. Ryabinkin
Two difficulties associated with the computations of thermal vibrational correlation functions are discussed. The first one is the lack of a well-behaved expression that is valid a…
Estimating Phosphorescent Emission Energies in Ir(III) Complexes using Large-Scale Quantum Computing Simulations
Scott N. Genin, Ilya G. Ryabinkin, Nathan R. Paisley +3
Quantum chemistry simulations that accurately predict the properties of materials are among the most highly anticipated applications of quantum computing. It is widely believed tha…
A posteriori corrections to the Iterative Qubit Coupled Cluster method to minimize the use of quantum resources in large-scale calculations
Ilya G. Ryabinkin, Artur F. Izmaylov, Scott N. Genin
The iterative qubit coupled cluster (iQCC) method is a systematic variational approach to solve the electronic structure problem on universal quantum computers. It is able to use a…
Unitary transformation of the electronic Hamiltonian with an exact quadratic truncation of the Baker-Campbell-Hausdorff expansion
Robert A. Lang, Ilya G. Ryabinkin, Artur F. Izmaylov
Application of current and near-term quantum hardware to the electronic structure problem is highly limited by qubit counts, coherence times, and gate fidelities. To address these…
Iterative Qubit Coupled Cluster approach with efficient screening of generators
Ilya G. Ryabinkin, Robert A. Lang, Scott N. Genin +1
An iterative version of the qubit coupled cluster (QCC) method [I.G. Ryabinkin et al., J. Chem. Theory Comput. 14, 6317 (2019)] is proposed. The new method seeks to find ground ele…
Quantum chemistry on quantum annealers
Scott N. Genin, Ilya G. Ryabinkin, Artur F. Izmaylov
Quantum chemistry calculations for small molecules on quantum hardware have been demonstrated to date only on universal-gate quantum computers, not quantum annealers. The latter de…
Symmetry adaptation in quantum chemistry calculations on a quantum computer
Ilya G. Ryabinkin, Scott N. Genin
Quantum chemistry calculations on a quantum computer frequently suffer from symmetry breaking: the situation when a state of assumed spin and number of electrons is contaminated wi…
Revising measurement process in the variational quantum eigensolver: Is it possible to reduce the number of separately measured operators?
Artur F. Izmaylov, Tzu-Ching Yen, Ilya G. Ryabinkin
Current implementations of the Variational Quantum Eigensolver (VQE) technique for solving the electronic structure problem involve splitting the system qubit Hamiltonian into part…
Qubit coupled-cluster method: A systematic approach to quantum chemistry on a quantum computer
Ilya G. Ryabinkin, Tzu-Ching Yen, Scott N. Genin +1
A unitary coupled-cluster (UCC) form for the wavefunction in the variational quantum eigensolver has been suggested as a systematic way to go beyond the mean-field approximation an…
Relation between fermionic and qubit mean fields in the electronic structure problem
Ilya G. Ryabinkin, Scott N. Genin, Artur F. Izmaylov
For quantum computing applications, the electronic Hamiltonian for the electronic structure problem needs to be unitarily transformed to a qubit form. We found that mean-field proc…
Constrained variational quantum eigensolver: Quantum computer search engine in the Fock space
Ilya G. Ryabinkin, Scott N. Genin, Artur F. Izmaylov
Variational quantum eigensolver (VQE) is an efficient computational method promising chemical accuracy in electronic structure calculations on a universal-gate quantum computer. Ho…
Improved method for generating exchange-correlation potentials from electronic wave functions
Egor Ospadov, Ilya G. Ryabinkin, Viktor N. Staroverov
Ryabinkin, Kohut, and Staroverov (RKS) [Phys. Rev. Lett. 115, 083001 (2015)] devised an iterative method for reducing many-electron wave functions to Kohn-Sham exchange-correlation…
Mixed quantum-classical dynamics using collective electronic variables: A better alternative to electronic friction theories
Ilya G. Ryabinkin, Artur F. Izmaylov
An accurate description of nonadiabatic dynamics of molecular species on metallic surfaces poses a serious computational challenge associated with a multitude of closely-spaced ele…
Topologically correct quantum nonadiabatic formalism for on-the-fly dynamics
Loic Joubert-Doriol, Janakan Sivasubramanium, Ilya G. Ryabinkin +1
On-the-fly quantum nonadiabatic dynamics for large systems greatly benefits from the adiabatic representation readily available from the electronic structure programs. However, fre…
On the inclusion of the diagonal Born-Oppenheimer correction in surface hopping methods
Rami Gherib, Liyuan Ye, Ilya G. Ryabinkin +1
The diagonal Born-Oppenheimer correction (DBOC) stems from the diagonal second derivative coupling term in the adiabatic representation, and it can have an arbitrary large magnitud…
Fast numerical evaluation of time-derivative nonadiabatic couplings for mixed quantum-classical methods
Ilya G. Ryabinkin, Jayashree Nagesh, Artur F. Izmaylov
We have developed a numerical differentiation scheme which eliminates evaluation of overlap determinants in calculating the time-derivative non-adiabatic couplings (TDNACs). Evalua…
Reduction of Electronic Wavefunctions to Kohn-Sham Effective Potentials
Ilya G. Ryabinkin, Sviataslau V. Kohut, Viktor N. Staroverov
A method for calculating the Kohn--Sham exchange-correlation potential, , from a given electronic wavefunction is devised and implemented. It requires on i…