Theoretical study of infrared spectrum for Ar–AgF complex

Abstract

In this work, we investigate the infrared spectrum of the Ar–AgF complex by using two methodologies. The first is performed by the computation of full-dimensional dynamics, and the second is obtained by solving the full-dimensional Hamiltonian separately. The vibrational shift, which shows excellent agreement with each other, is determined to be 29.11 cm–1 from the former methodology and 29.14 cm–1 from the latter methodology upon AgF excitation in the Ar–AgF complex. For the latter methodology, the contribution from intermolecular interactions is determined to be a positive value of 39.45 cm–1, while that from intramolecular interactions is only 0.51 cm–1, which is the difference of the intermolecular force acting on the AgF monomer. The contribution from intermolecular-intramolecular coupling interactions is determined to be a negative value of –10.82 cm–1. Since the full-dimensional Hamiltonian of the van der Waals dimer can be divided into three sub-units, the latter methodology is named the 3H-solution model. Based on the potential energy surfaces and bound state calculations, infrared spectra were predicted for the fundamental and the first two combination bands of the Ar–AgF complex.