Beyond MP2 initialization for unitary coupled cluster quantum circuits

The unitary coupled cluster singles and doubles (UCCSD) ansatz is a promising approach to prepare accurate quantum states for use in quantum algorithms. In this paper, we compared the performance of two methods for generating the initial UCCSD circuit parameters: CCSD and MP2. Our results, obtained through an efficient sparse wavefunction circuit solver, show that UCCSD circuits with CCSD parameterizations significantly outperformed those with MP2 parameterizations for systems of up to 64 qubits. These findings suggest that CCSD should be the preferred choice for generating initial parameters.