Theoretical ROVibrational Energies (TROVE): A robust numerical approach to the calculation of rovibrational energies for polyatomic molecules

ExoMol line lists – XV. A new hot line list for hydrogen peroxide

“…Theoretical ROVibrational Energies (TROVE) (Yurchenko et al 2007) was employed to compute the ro-vibrational energies of H2O2. TROVE is a variational nuclear motion solver and was used to successfully produce the room temperature H2O2 line list as well as hot line lists for NH3 (Yurchenko et al 2011a), CH4 ), PH3 (Sousa-Silva et al 2015, H2CO (Al-Refaie et al 2015b) and SO3 (Underwood et al 2016).…”

“…However, the computational cost is greatly reduced for rotationally excited states by using TROVE. Convergence of the KEO usually requires an expansion order of 6 or 8 (Yurchenko et al 2007); 6 being chosen for this work and 8 for the potential energy expansion as suggested from a previous H2O2 calculation by Polyansky et al (2013).…”

ExoMol line lists – VIII. A variationally computed line list for hot formaldehyde

“…The TROVE program suite (Yurchenko et al 2007) is employed to compute our formaldehyde line list as well to perform the least-squares fit of the ab initio PES discussed above. TROVE is designed to compute variational ro-vibrational energy levels, associated eigenfunctions and transition intensities for molecules of arbitrary structure.…”

“…In this work we use a kinetic expansion order of 6 for optimal convergence while providing reasonable computation times and similarly, we use a potential energy expansion order of 8. In TROVE, the primitive vibrational basis set is represented by a symmetrized product of six one-dimensional vibrational functions φn 1 (r ℓ 1 ), φn 2 (r ℓ 2 ), φn 3 (r ℓ 3 ), φn 4 (θ ℓ 1 ), φn 5 (θ ℓ 2 ), and φn 6 (τ ), where ni denotes the associated local mode vibrational quanta, {r ℓ 1 , r ℓ 2 , r ℓ 3 , θ ℓ 1 , θ ℓ 2 } are linearized versions (Yurchenko et al 2007;Bunker & Jensen 1998) of the coordinates {rCO, rCH 1 , rCH 2 , θOCH 1 , and θOCH 2 }, respectively, and τ is the dihedral angle between the OCH1 and OCH2 planes. The functions φn i (qi) are obtained by solving the corresponding 1D Schrödinger equation (Yurchenko et al 2007) for the vibrational motion associated with the corresponding coordinate qi ∈ {r ℓ 1 , r ℓ 2 , r ℓ 3 , θ ℓ 1 , θ ℓ 2 , τ }, with the other coordinates held fixed at their equilibrium values, where the Numerov-Cooley method (Noumerov 1924;Cooley 1961) is used.…”

“…The goal of this work is to bridge this gap. We use the variational program TROVE (Yurchenko et al 2007) in conjunction with an initial potential energy surface (PES) obtained 'spectroscopically' by Yachmenev et al (2011) and a new ab initio dipole moment surface (DMS) for formaldehyde and generate an extensive line list for H2 12 C 16 O applicable for the temperatures up to T = 1500 K. In the following H2CO and formaldehyde will refer to the main isotopologue H2 12 C 16 O.…”