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[Licence| Download | New Version Template] adti_v1_0.tar.gz(933 Kbytes)
Manuscript Title: DVR3D: a program suite for the calculation of rotation-vibration spectra of triatomic molecules.
Authors: J. Tennyson, M.A. Kostin, P. Barletta, G.J. Harris, O.L. Polyansky, J. Ramanlal, N.F. Zobov.
Program title: DVR3D
Catalogue identifier: ADTI_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 163(2004)85
Programming language: Fortran 90.
Computer: PC, Sunfire V750, V880, Compaq, IBM p690, Origin 2000.
Operating system: UNIX, Linux, AIX.
RAM: Case dependent.
Keywords: Molecular physics, Vibrations, Molecular spectra, Infrared, Microwave, Variational principle, Expectation values, Born-Oppenheimer approximation, Triatomic molecules.
PACS: 33.20, 39.30.
Classification: 16.3.

Nature of problem:
DVR3D calculates the bound vibrational or Coriolis decoupled ro-vibrational states of a triatomic system in body-fixed Jacobi (scattering) or Radau coordinates [1,2].

Solution method:
All coordinates are treated in a discrete variable representation (DVR). The angular coordinate uses a DVR based on (associated) Legendre polynomials and the radial coordinates utilise a DVR based on either Morse oscillator-like or spherical oscillator functions. Intermediate diagonalisation and truncation is performed on the hierarchical expression of the Hamiltonian operator to yield the final secular problem. DVR3DRJZ provides the vibrational wavefunctions necessary for ROTLEV2, ROTLEV3B or ROTLEV3Z to calculate rotationally excited states, DIPOLE3 to calculate ro-vibrational transition strengths and XPECT3 to compute expectation values.

Restrictions:
(1) The size of the final Hamiltonian matrix that can practically be diagonalised.
(2) The order of integration in the radial coordinates that can be dealt with within the machine exponent range. Some adjustment in the code may be necessary when large order Gauss-Laguerre quadrature is used.

Unusual features:
A user supplied subroutine containing the potential energy as an analytic function is a program requirement.

Additional comments:
DVR3D is a suite of programs. The tar.gz file for ADTI contains copies of each of the programs in the suite and the test data and results. Each of the 7 main programs in the suite is also held separately in the library under the Catalogue Identities ACNE_v3_0, ADAL_v2_0, ADAM_v2_0, ADTE_v1_0, ADAN_v2_0, ABLA_v3_0 and ADTH_v1_0.

Running time:
Case dependent but usually dominated by the final (3D) matrix diagonalisation. The test runs take minutes on a fast PC.

References:
[1] H.Y. Mussa and J. Tennyson, Computer Phys. Comms., 128, 434(2000).
[2] J. Tennyson and B. T. Sutcliffe, Intern. J. Quantum Chem. 42(1992)941.