Variational Quantum Eigensolver for Estimating the Equilibrium Configuration of Molecules

Herbert Díaz Pontificia Universidad Católica de Chile

With the emergence of new technologies, quantum computing opens up a new world of possibilities, capable of tackling computationally complex problems such as optimization, combinatorial challenges [1], and molecular simulations [2]. One of the current challenges is the noise and intermediate scale reached by quantum computers (NISQ era), where errors associated with quantum phenomena prevent several algorithms from demonstrating their full utility. A way to leverage current quantum computers is through the Variational Quantum Eigensolver (VQE) [3], a quantum-classical algorithm utilized to compute the expectation value of the minimum energy of the electronic structure for molecules. By mapping fermionic systems to qubits, we use this algorithm to obtain the equilibrium energy and geometric configuration of diatomic molecules such as H2, LiH, and HF, and for the triatomic molecules H2O and O3.