Editing Computational chemistry (section)

=== Quantum Computational Chemistry ===
{{Main article|Quantum computational chemistry}}

[[Quantum computational chemistry]] aims to exploit [[quantum computing]] to simulate chemical systems, distinguishing itself from the QM/MM (Quantum Mechanics/Molecular Mechanics) approach.<ref>{{Cite journal |last1=Abrams |first1=Daniel S. |last2=Lloyd |first2=Seth |date=1999-12-13 |title=Quantum Algorithm Providing Exponential Speed Increase for Finding Eigenvalues and Eigenvectors |url=https://link.aps.org/doi/10.1103/PhysRevLett.83.5162 |journal=Physical Review Letters |volume=83 |issue=24 |pages=5162–5165 |doi=10.1103/PhysRevLett.83.5162|arxiv=quant-ph/9807070 |bibcode=1999PhRvL..83.5162A |s2cid=118937256 }}</ref> While QM/MM uses a hybrid approach, combining quantum mechanics for a portion of the system with classical mechanics for the remainder, quantum computational chemistry exclusively uses quantum computing methods to represent and process information, such as Hamiltonian operators.<ref>{{Cite book |last=Feynman |first=Richard P. |editor-first1=Tony |editor-first2=Robin W. |editor-last1=Hey |editor-last2=Allen |url=https://www.taylorfrancis.com/books/mono/10.1201/9780429500442/feynman-lectures-computation-richard-feynman |title=Feynman Lectures On Computation |date=2019-06-17 |publisher=CRC Press |isbn=978-0-429-50044-2 |location=Boca Raton |doi=10.1201/9780429500442|s2cid=53898623 }}</ref>

Conventional computational chemistry methods often struggle with the complex quantum mechanical equations, particularly due to the exponential growth of a quantum system's wave function. Quantum computational chemistry addresses these challenges using [[Quantum computing|quantum computing methods]], such as qubitization and [[quantum phase estimation]], which are believed to offer scalable solutions.<ref name="Nielsen-2010">{{Cite book |last1=Nielsen |first1=Michael A. |title=Quantum computation and quantum information |last2=Chuang |first2=Isaac L. |date=2010 |publisher=Cambridge university press |isbn=978-1-107-00217-3 |edition=10th anniversary |location=Cambridge}}</ref>

Qubitization involves adapting the Hamiltonian operator for more efficient processing on quantum computers, enhancing the simulation's efficiency. Quantum phase estimation, on the other hand, assists in accurately determining energy eigenstates, which are critical for understanding the quantum system's behavior.<ref>{{Cite journal |last1=McArdle |first1=Sam |last2=Endo |first2=Suguru |last3=Aspuru-Guzik |first3=Alán |last4=Benjamin |first4=Simon C. |last5=Yuan |first5=Xiao |date=2020-03-30 |title=Quantum computational chemistry |journal=Reviews of Modern Physics |volume=92 |issue=1 |pages=015003 |doi=10.1103/RevModPhys.92.015003|doi-access=free |arxiv=1808.10402 |bibcode=2020RvMP...92a5003M }}</ref>

While these techniques have advanced the field of computational chemistry, especially in the simulation of chemical systems, their practical application is currently limited mainly to smaller systems due to technological constraints. Nevertheless, these developments may lead to significant progress towards achieving more precise and resource-efficient quantum chemistry simulations.<ref name="Nielsen-2010" />