Modelling Actinides Chemistry with Trapped Ion Quantum Computers

Actinides are important elements that are involved in many chemical applications, such as nuclear energy and power generation and single molecule magnets. However, modelling the actinides chemistry is very challenging. In this context, quantum computers are emerging as a promising platform for performing accurate electronic structure calculations, such as complete active space methods with large active spaces.

In this project, we have used quantum computation to calculate the energy of several molecules containing actinides which are involved in the plutonium oxidation. We devised chemical models, performed classical CASSCF calculations and then carried out quantum calculations on both emulator and Quantinuum H2 hardware series. We have employed the stochastic Quantum Phase Estimation and the Quantum Computed Moments algorithms. The largest active space we have been able to run on hardware was 18 qubits. We have found promising results from the hardware output, yielding energies at chemical accuracy or close to it.