Accurate and Efficient Quantum Computations of Molecular Properties Using Daubechies Wavelet Molecular Orbitals: A Benchmark Study against Experimental Data
Journal
PRX Quantum 3, 020360 (2022)
Journal Volume
3
Journal Issue
2
Date Issued
2022-05-29
Author(s)
Cheng-Lin Hong
Ting Tsai
Jyh-Pin Chou
Peng-Jen Chen
Pei-Kai Tsai
Yu-Cheng Chen
En-Jui Kuo
David Srolovitz
Alice Hu
Abstract
Although quantum computation (QC) is regarded as a promising numerical method
for computational quantum chemistry, current applications of quantum-chemistry
calculations on quantum computers are limited to small molecules. This
limitation can be ascribed to technical problems in building and manipulating
more qubits and the associated complicated operations of quantum gates in a
quantum circuit when the size of the molecular system becomes large. As a
result, reducing the number of required qubits is necessary to make QC
practical. Currently, the minimal STO-3G basis set is commonly used in
benchmark studies because it requires the minimum number of spin orbitals.
Nonetheless, the accuracy of using STO-3G is generally low and thus cannot
provide useful predictions. We propose to adopt Daubechies wavelet functions as
an accurate and efficient method for QCs of molecular electronic properties. We
demonstrate that a minimal basis set constructed from Daubechies wavelet basis
can yield accurate results through a better description of the molecular
Hamiltonian, while keeping the number of spin orbitals minimal. With the
improved Hamiltonian through Daubechies wavelets, we calculate vibrational
frequencies for H$_2$ and LiH using quantum-computing algorithm to show that
the results are in excellent agreement with experimental data. As a result, we
achieve quantum calculations in which accuracy is comparable with that of the
full configuration interaction calculation using the cc-pVDZ basis set, whereas
the computational cost is the same as that of a STO-3G calculation. Thus, our
work provides a more efficient and accurate representation of the molecular
Hamiltonian for efficient QCs of molecular systems, and for the first time
demonstrates that predictions in agreement with experimental measurements are
possible to be achieved with quantum resources available in near-term quantum
computers.
Subjects
EIGENSOLVER; PSI4; Quantum Physics; Quantum Physics; Physics - Chemical Physics
Publisher
AMER PHYSICAL SOC
Description
14 pages, 5 figures, Accepted by PRX Quantum
Type
journal article