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arXiv · 1008.3451

Quantum computing applied to calculations of molecular energies: CH2 benchmark

Libor Veis·Jiří Pittner
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Abstract

Quantum computers are appealing for their ability to solve some tasks much faster than their classical counterparts. It was shown in [Aspuru-Guzik et al., Science 309, 1704 (2005)] that they, if available, would be able to perform the full configuration interaction (FCI) energy calculations with a polynomial scaling. This is in contrast to conventional computers where FCI scales exponentially. We have developed a code for simulation of quantum computers and implemented our version of the quantum full configuration interaction algorithm. We provide a detailed description of this algorithm and the results of the assessment of its performance on the four lowest lying electronic states of CH2 molecule. This molecule was chosen as a benchmark, since its two lowest lying 1A1 states exhibit a multireference character at the equilibrium geometry. It has been shown that with a suitably chosen initial state of the quantum register, one is able to achieve the probability amplification regime of the iterative phase estimation algorithm even in this case.

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Libor Veis, Jiří Pittner. 2010-09-21. Quantum computing applied to calculations of molecular energies: CH2 benchmark. https://doi.org/10.1063/1.3503767

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