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Manuscript Title: DVR3D: a program suite for the calculation of rotation-vibration spectra of triatomic molecules (ROTLEV3B).
Authors: J. Tennyson, M.A. Kostin, P. Barletta, G.J. Harris, O.L. Polyansky, J. Ramanlal, N.F. Zobov.
Program title: ROTLEV3B
Catalogue identifier: ADTD
Journal reference: Comput. Phys. Commun. 163(2004)85
Programming language: Fortran 90.
Computer: PC, Compaq, Sunfire V750, V880, 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.

Subprograms used:
Cat Id Title Reference
ADTB DVR3DRJZ CPC 163(2004)85

Other versions:
Cat Id Title Reference
ADAM ROTLEV3B CPC 86(1995)175

Nature of problem:
ROTLEV3B performs the second step in a two-step variational calculation for the bound ro-vibrational levels of a triatomic system represented in symmetrised Radau coordinates using a bisector embedding [2].

Solution method:
A basis is constructed from the solutions of the Coriolis decoupled problem provided by DVR3DRJZ. The problem is constructed entirely within the DVR. The Hamiltonian matrix can be diagonalised iteratively or in core.

The size of matrix that can practically be diagonalised.

Unusual features:
Most data is read directly from DVR3DRJZ. ROTLEV3B can provide data to drive DIPOLE3 and/or XPECT3.

Additional comments:
The code has been extensively vectorised. A parallel version of the code, PROTLEV3B has been developed [1], contact the first author for details.
ROTLEV3B forms part of the DVR3D suite of programs. The complete suite is catalogued under the identifier ADTI. The tar.gz file for ADTI contains sample input and output data which can be used to test all the programs in the suite.

Running time:
Case dependent. The sample data takes a few minutes on a fast PC.

[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.