SpectrumSDT: A program for parallel calculation of coupled rotational-vibrational energies and lifetimes of bound states and scattering resonances in triatomic systems

Abstract We present SpectrumSDT – a program for calculations of energies and lifetimes of bound rotational-vibrational states below and scattering resonances above the dissociation threshold on a global potential energy surface of a triatomic system, which may include stable molecules, weekly-bound van-der-Waals complexes, and unbound atom + diatom scattering systems. Large-amplitude vibrational motion is treated explicitly using hyper-spherical coordinates. Three options for the rotational-vibrational interaction are supported: uncoupled (symmetric top rotor), partially coupled (to include interaction between several nearest states only) and full-coupled (vibrating asymmetric-top rotor). In addition to energies and lifetimes, SpectrumSDT is able to integrate ro-vibrational wave functions over the user-defined regions of potential energy surface, which helps to classify these states. In this release of the code, SpectrumSDT is limited to ABA-type molecules with wave functions that do not extend into the regions near Eckart singularities . Program summary Program title: SpectrumSDT CPC Library link to program files: https://doi.org/10.17632/9gftxjs4yk.1 Developer's repository link: https://github.com/IgorGayday/SpectrumSDT Licensing provisions: GNU General Public License 3 (GPL) Programming language: Fortran Nature of problem: Calculations of energies and lifetimes of bound rotational-vibrational states below and scattering resonances above the dissociation threshold on a global potential energy surface of a triatomic system, which may include stable molecules, weekly-bound van-der-Waals complexes, and unbound atom + diatom scattering systems. Solution method: A Hamiltonian matrix is built in APH coordinates using an optimal 2D basis set, adjusted for a given problem. A complex absorbing potential (CAP) is added to define a boundary condition for calculation of scattering resonances above the dissociation threshold. The eigenstates of the Hamiltonain matrix are found using a state-of-the-art iterative eigensolver. Restrictions: The present version is restricted to ABA-molecules and wave functions that do not extend into linear and equilateral triangle configurations. Additional comments including restriction and unusual features: Probabilities and lifetimes of the wave functions can be calculated in user-defined regions on the PES, which allows to analyze their localization properties (i.e. automatic isotopomer assignment) and obtain channel-specific lifetimes for scattering resonances.

[1]  J. Light,et al.  Localized representations for large amplitude molecular vibrations , 1988 .

[2]  G. Domínguez,et al.  The physical chemistry of mass-independent isotope effects and their observation in nature. , 2012, Annual review of physical chemistry.

[3]  C. Greene,et al.  Unified theoretical treatment of dissociative recombination of D3h triatomic ions: Application to H3+ and D3+ , 2003 .

[4]  A. Teplukhin,et al.  Visualization of Potential Energy Function Using an Isoenergy Approach and 3D Prototyping , 2015 .

[5]  T. Carrington,et al.  Calculated vibrational states of ozone up to dissociation. , 2016, The Journal of chemical physics.

[6]  A. Teplukhin,et al.  Efficient method for calculations of ro-vibrational states in triatomic molecules near dissociation threshold: Application to ozone , 2016 .

[7]  A. Teplukhin,et al.  The role of rotation-vibration coupling in symmetric and asymmetric isotopomers of ozone. , 2020, The Journal of chemical physics.

[8]  Robert B. Walker,et al.  Metastable states of ozone calculated on an accurate potential energy surface , 2003 .

[9]  R. Marcus,et al.  Coriolis coupling as a source of non-RRKM effects in ozone molecule: Lifetime statistics of vibrationally excited ozone molecules. , 2010, The Journal of chemical physics.

[10]  Konrad Mauersberger,et al.  Measurement of heavy ozone in the stratosphere , 1981 .

[11]  Jeremy M. Hutson,et al.  bound and field: Programs for calculating bound states of interacting pairs of atoms and molecules , 2018, Comput. Phys. Commun..

[12]  R. Bacis,et al.  THE OZONE MOLECULE : INFRARED AND MICROWAVE SPECTROSCOPY , 1998 .

[13]  A. Teplukhin,et al.  Several Levels of Theory for Description of Isotope Effects in Ozone: Symmetry Effect and Mass Effect. , 2018, The journal of physical chemistry. A.

[14]  Ed Anderson,et al.  LAPACK Users' Guide , 1995 .

[15]  Andrés Tomás,et al.  Parallel Arnoldi eigensolvers with enhanced scalability via global communications rearrangement , 2007, Parallel Comput..

[16]  E. F. Hayes,et al.  HYPERSPHERICAL SURFACE FUNCTIONS FOR NONZERO TOTAL ANGULAR MOMENTUM. I. ECKART SINGULARITIES , 1999 .

[17]  Jonathan Tennyson,et al.  DVR3D: a program suite for the calculation of rotation-vibration spectra of triatomic molecules , 2004, Comput. Phys. Commun..

[18]  F. Machado,et al.  Accurate rovibrational energies of ozone isotopologues up to J = 10 utilizing artificial neural networks. , 2018, The Journal of chemical physics.

[19]  A. Teplukhin,et al.  A full-dimensional model of ozone forming reaction: the absolute value of the recombination rate coefficient, its pressure and temperature dependencies. , 2016, Physical chemistry chemical physics : PCCP.

[20]  Wenwu Chen,et al.  Parallel implementation of efficient preconditioned linear solver for grid-based applications in chemical physics. I: Block Jacobi diagonalization , 2006, J. Comput. Phys..

[21]  I. Gayday,et al.  Influence of the Coriolis effect on the properties of scattering resonances in symmetric and asymmetric isotopomers of ozone. , 2020, Physical chemistry chemical physics : PCCP.

[22]  J. Tennyson,et al.  Triatom: programs for the calculation of ro-vibrational spectra of triatomic molecules , 1993 .

[23]  Ahmed F. Al-Refaie,et al.  The ExoMol database: Molecular line lists for exoplanet and other hot atmospheres , 2016, 1603.05890.

[24]  D. Krankowsky,et al.  Kinetic origin of the ozone isotope effect: a critical analysis of enrichments and rate coefficients , 2001 .

[25]  A. Császár,et al.  Rotating full- and reduced-dimensional quantum chemical models of molecules. , 2011, The Journal of chemical physics.

[26]  Wenwu Chen,et al.  Parallel implementation of efficient preconditioned linear solver for grid-based applications in chemical physics. II: QMR linear solver , 2006, J. Comput. Phys..

[27]  A. Teplukhin,et al.  Interactive tool for visualization of adiabatic adjustment in APH coordinates for computational studies of vibrational motion and chemical reactions , 2014 .

[28]  Hua Guo,et al.  Communication: An accurate global potential energy surface for the ground electronic state of ozone. , 2013, The Journal of chemical physics.

[29]  Jeremy M. Hutson,et al.  molscat: A program for non-reactive quantum scattering calculations on atomic and molecular collisions , 2018, Comput. Phys. Commun..

[30]  G. A. Parker,et al.  Quantum reactive scattering in three dimensions using hyperspherical (APH) coordinates. Theory , 1987 .

[31]  Ronnie Kosloff,et al.  MAPPED FOURIER METHODS FOR LONG-RANGE MOLECULES : APPLICATION TO PERTURBATIONS IN THE RB2(0U+) PHOTOASSOCIATION SPECTRUM , 1999 .

[32]  A. Császár,et al.  Toward automated variational computation of rovibrational resonances, including a case study of the H2 dimer. , 2019, Journal of chemical theory and computation.

[33]  A. Teplukhin,et al.  Several levels of theory for description of isotope effects in ozone: Effect of resonance lifetimes and channel couplings. , 2018, The Journal of chemical physics.

[34]  David E. Manolopoulos,et al.  Derivation and reflection properties of a transmission-free absorbing potential , 2002 .

[35]  M. Thiemens,et al.  The Mass-Independent Fractionation of Oxygen: A Novel Isotope Effect and Its Possible Cosmochemical Implications , 1983, Science.

[36]  A. Teplukhin,et al.  The ratio of the number of states in asymmetric and symmetric ozone molecules deviates from the statistical value of 2. , 2019, The Journal of chemical physics.

[37]  Vicente Hernández,et al.  SLEPc: A scalable and flexible toolkit for the solution of eigenvalue problems , 2005, TOMS.

[38]  A. Teplukhin,et al.  Properties of Feshbach and "shape"-resonances in ozone and their role in recombination reactions and anomalous isotope effects. , 2018, Faraday discussions.

[39]  Hua Guo,et al.  New ab initio adiabatic potential energy surfaces and bound state calculations for the singlet ground X̃(1)A1 and excited C̃(1)B2(2(1)A(')) states of SO2. , 2016, The Journal of chemical physics.

[40]  A. Császár,et al.  Toward black-box-type full- and reduced-dimensional variational (ro)vibrational computations. , 2009, The Journal of chemical physics.

[41]  P. Fleurat‐Lessard,et al.  Dynamical studies of the ozone isotope effect: A status report. , 2006, Annual review of physical chemistry.

[42]  W. M. Haynes.  CRC Handbook of Chemistry and Physics , 1990 .

[43]  R. Marcus,et al.  Coriolis coupling as a source of non-RRKM effects in triatomic near-symmetric top molecules: Diffusive intramolecular energy exchange between rotational and vibrational degrees of freedom. , 2010, The Journal of chemical physics.