Computational studies of quantum chemical problems

Ivan Kassal

Martin Andersson, Mark Jones, Kurt Valentin Mikkelsen +2 more

Chemical process design has for long been benefiting from computer-aided methods and tools to develop new processes and services that can meet the needs of society. Chemical and biomolecular product design could also benefit from the use of computer-aided solution strategies and computational power to efficiently solve the problems at various scales as the complexity and size of problems grow. In this context, new modes of computation such as quantum computing are receiving increasing attention. While quantum computing has been in development for quite some time, the development of the technology to the point of making commercial use of such resources is quite recent, and still quite limited in scope. However, projections point to a rapid development of quantum computing resources becoming available to academia and industry, which opens potential application areas in chemical and biomolecular product design. With the advent of hybrid algorithms that are able to take advantage of both classical computing and quantum computing resources, as quantum computing grows, more and more problems relevant for chemical product design will become solvable. In this paper, some perspectives are given by identifying a set of needs and challenges for a selected set of opportunities, such as quantum chemistry-based property prediction, protein folding, complex multi-step chemical reactions, and molecular reaction dynamics.

Ajit J. Thakkar

Ignacio Loaiza

Even though the physical equations that model chemical systems are known, the complexity of solving, and sometimes even representing such equations, escalates exponentially with the system size for an arbitrary chemical system. However, many different approximations can be made and efficient algorithms found for the accurate description of some chemical systems of interest with reasonable computational effort. In this work, we propose efficient algorithms for the solution of three problems of chemical interest, namely: the electronic structure problem using quantum computers, the simulation of chemical reactions on metallic surfaces, and modelling the absorption of solar radiation by light harvesting molecules. All of the proposed algorithms work within larger frameworks. We start by discussing the importance of each given problem, after which we cover the necessary background for all the used frameworks and show the details on how our proposed algorithms make these frameworks more efficient.