Computational high-resolution molecular spectroscopy of iminophosphane, HNPH, a candidate for astrophysical observations

The (ro)vibrational spectra of trans and cis-iminophosphane have been studied by variational ab initio methods based on the Watson Hamiltonian. Rovibrational configuration interaction theory (RVCI) relying on a potential energy surface including up to 4-mode coupling terms being obtained from explicitly correlated coupled-cluster theory, CCSD(T)-F12b, and further corrections for core correlation effects and high-order coupled-cluster terms, has been used to compute the microwave spectra of these molecules as well as rovibrational transitions up to 3500 cm −1 . These calculations may guide astrophysical observations and new lab experiments of these recently synthesized molecules.