title: Global ab initio ground-state potential energy surface of N4.
abstract: We present a global ground-state potential energy surface for N4 suitable for treating high-energy vibrational-rotational energy transfer and collision-induced dissociation in N2-N2 collisions. To obtain the surface, complete active space second-order perturbation theory calculations were performed for the ground singlet state with an active space of 12 electrons in 12 orbitals and the maug-cc-pVTZ triple zeta basis set. About 17,000 ab initio data points have been calculated for the N4 system, distributed along nine series of N2 + N2 geometries and three series of N3 + N geometries. The six-dimensional ground-state potential energy surface is fitted using least-squares fits to the many-body component of the electronic energies based on permutationally invariant polynomials in bond order variables.
authors.affiliation: Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Paukku
authors.forename: Ke R
authors.initials: KR
authors.lastname: Yang
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Varga
authors.forename: Donald G
authors.initials: DG
authors.lastname: Truhlar