=============================================================================== ExoMol Line List XXI: Nitric Oxide (NO) MNRAS 2017 A. Wong, S.N. Yurchenko, P. Bernath, H. S. P. Mueller, S. McConkey, Jonathan Tennyson Line lists for the ground electronic ground state for the parent isotopologue of nitric oxide and five other major isotopologues are presented. The line lists are constructed using empirical energy levels (and line positions) and high-level ab inito intensities. The energy levels were obtained using a combination of two approaches, from an effective Hamiltonian and from solving the rovibronic Schroedinger equation variationally. The effective hamiltonian model was obtained through a fit to the experimental line positions of NO available in the literature for all six isotopologues using the programs SPFIT and SPCAT. The variational model was built through a least squares fit of the ab inito potential and spin-orbit curves to the experimentally derived energies and experimental line positions of the main isotopologue only using the Duo program. The ab inito potential energy, spin-orbit and dipole moment curves (PEC, SOC and DMC) are computed using high-level ab inito methods and the MARVEL method is used to obtain energies of NO from experimental transition frequencies. The line lists are constructed for each isotopologue based on the use of the most accurate energy levels and the ab inito DMC. Each line list covers a wavenumber range from 0 - 40,000 cm-1 with approximately 22,000 rovibronic states and 2.3 - 2.6 million transitions extending to J = 184.5 and v = 51. The computed NO line lists are the most comprehensive to date, covering a wider wavenumber and temperature range compared to both the HITRAN and HITEMP databases. These line lists are also more accurate than those used in HITEMP. The full line lists are available from www.exomol.com. Description: The states file .states contains lists of rovibronic states. Each state is labelled with the total angular momentum, state degeneracy, total parity, vibrational quantum number, projection of the electronic, spin and total angular momenta. Each state has a unique number, which is the number of the row in which it appears in the file. This number is the means by which the state is related to the second part of the data system, the transitions files. The lifetimes and Lande-g factors are also provided. The transition file .trans contains four columns: the reference number in the energy file of the upper state, that of the lower state, the Einstein A coefficient of the transition and the transition wavenumber. These entries are ordered by increasing frequency. The energy file and the transitions files are bzipped, and need to be extracted before use. The .pf files contain the partition function (0...5000 K) tabulated in steps of 1 K. The pf_param.dat contains unitless expansion parameters Byte-by-byte description of file: .trans ------------------------------------------------------------------------------- Bytes Format Units Label Explanations ------------------------------------------------------------------------------- 1 - 12 I12 --- i" Upper state ID 14 - 25 I12 --- i' Lower state ID 27 - 36 E10.4 s-1 A Einstein A-coefficient of the transition 38 - 52 f15.6 cm-1 nu Transition wavenumber ------------------------------------------------------------------------------- Byte-by-byte description of the states file: .states ------------------------------------------------------------------------------- Bytes Format Units Label Explanations ------------------------------------------------------------------------------- 1- 12 i12 --- N State ID, non-negative integer index 14- 25 i12 cm-1 E State energy term value in cm-1 27- 32 i6 --- g Total state degeneracy 34- 40 f7.1 --- J [0/184.5] J-quantum number, the total angular momentum excluding nuclear spin 42- 53 e12.4 s-1 tau Life time 56- 64 f9.6 --- g Lande g-factor 66- 66 a1 --- +/- Total parity 68- 68 a1 --- e/f Rotationless-parity 71- 74 a4 --- State Notation of the electronic state 76- 80 i5 --- v State vibrational quantum number 82- 85 i4 --- Lambda Projection of electonic angular momentum 87- 91 f5.1 --- Sigma Projection of the electronic spin 93- 97 f5.1 --- Omega Projection of the total angular momentum 101-101 a1 --- e/c Empirical (e) or calculated (c) ------------------------------------------------------------------------------- Byte-by-byte description of the partition function files *.pf ------------------------------------------------------------------------------- Bytes Format Units Label Explanations ------------------------------------------------------------------------------- 1- 13 f13.3 K T Temperature 15- 34 e20.8 --- Q Partition function ------------------------------------------------------------------------------ Contacts: J. Tennyson, j.tennyson@ucl.ac.uk S.N. Yurchenko, s.yurchenko@ucl.ac.uk ===============================================================================