Experimental Assessment of Combined Contribution of Coal Mass Diffusion and Seepage to Methane Migration under In Situ Stress Conditions

Advances in quantum computation for electronic structure, and particularly heuristic quantum algorithms, create an ongoing need to characterize the performance and limitations of these methods. Here we discuss some potential pitfalls connected with the use of hardware-efficient Ansa''tze in variational quantum simulations of electronic structure. We illustrate that hardwareefficient Ansa''tze may break Hamiltonian symmetries and yield nondifferentiable potential energy curves, in addition to the wellknown difficulty of optimizing variational parameters. We discuss the interplay between these limitations by carrying out a comparative analysis of hardware-efficient Ansa''tze versus unitary coupled cluster and full configuration interaction, and of secondand first-quantization strategies to encode Fermionic degrees of freedom to qubits. Our analysis should be useful in understanding potential limitations and in identifying possible areas of improvement in hardware-efficient Ansa''tze.