Granting institution:

          OTKA (Hungarian Scientific Research Fund)

Grant no.:

          NK 83583

Title of the proposal:

          The fourth age of quantum chemistry


          Five years (2011–2016)

Project leader:

          Attila G. Császár


Project description:

The goal is the development and extension of our “in-house” variational quantum chemical nuclear motion protocols and codes and the application of the new approaches and computational techniques to chemical systems and problems which could not be treated before.  Specific parts of the proposal are as follows:

(1)       Nuclear motions in adiabatic and non-adiabatic treatments.

(2)       Advancement of nuclear motion computations in Cartesian coordinates with the help of projection operators.

(3)       Exploration of the sequential summation technique, especially within the frame of the finite basis representation of the rotational-vibrational Hamiltonian.

(4)       The role of symmetry in nuclear motion computations with a view on treating large(r) symmetric systems.

(5)       Computation of rotational motions and rotational-vibrational energy levels for arbitrary systems and excitation energies, in full and reduced dimensional spaces.

(6)       Development of protocols (CAP and CCS) allowing the efficient and automatic computation of resonance states. Application of the protocol to polyatomic molecules, in the beginning to H3+ and H2O.

(7)       Developing computational quantum reaction kinetics, determination of quantum mechanical reaction rate coefficients (with emphasis on the reactions H2 + H = H + H2 and CH4 + OH = CH3 + H2O and their isotopically substituted analogs).

(8)       Quasi-classical reaction dynamics computations, with special emphasis on SN2 reactions on carbon centers.

(9)       Complete spectroscopy of the following astrochemically relevant systems (ab initio and MARVEL energy levels): H2O, NH3, CH4, and C2H4, determination of as complete line-lists for these species as possible.

(10)  Spectroscopy of molecular clusters (e.g., water dimer and trimer).

(11)  Determination of new PESs for polyatomic reactions and their utilization in reaction dynamics.

(12)  Variational computation of effective spectroscopic (rotational and centrifugal distortion) contants of perturbational origin and temperature-dependent, effective molecular structures.