Response to “Comment on ‘Theoretical examination of QED Hamiltonian in relativistic molecular orbital theory’” [J. Chem. Phys. 160, 187101 (2024)]

Comment 1 on our recently published paper, 2 this article provides our responses to the raised questions.The Comment poses several questions, and the purpose of this article is to address and resolve those questions.Specifically, our focus encompasses three key aspects regarding the validity of our paper, referred to as Paper 2 in accordance with the assigned reference number (Ref.2).1.In Paper 2, we employed three types of contractions: the constantly null contraction (CNC), the charge-conjugated contraction (CCC), and the conventional contraction (cC).These contractions were utilized solely formally during the construction (definition) process of the QED Hamiltonians from the virtual pair approximation (VPA) Hamiltonian.Once the QED Hamiltonians, for the MO-CNC case as an example,