LEVEL is R.J. Le Roy's program for calculating the eigenvalues of bound and quasibound levels of any smooth one-dimensional or radial potential, together with (as desired) expectation values and centrifugal distortion constants for specified levels, and Franck-Condon factors or matrix elements of specified powers of a chosen distance variable (and hence of quantities expanded as power series in this variable) or of a user-specified radial function defined by interpolating over a set of read-in points. Such off-diagonal matrix elements may couple levels of the same potential or levels of two different potentials, subject to rotational selection rules specified by the user's input data file. Significant features of the program include the abilities:
  1. to automatically locate and calculate the widths or tunneling lifetimes of quasibound (or orbiting resonance, or tunneling-predissociation) levels,
  2. to calculate diatomic molecule centrifugal distortion constants for levels of a given potential,
  3. to locate levels with dominant amplitude over either well of a double minimum potential,
  4. to automatically locate and calculate expectation values for all vibrational-rotational levels of any well-behaved single-minimum, ``shelf state'' or double minimum potential, and
  5. to automatically locate and generate radiative lifetimes for transitions from vibration-rotation levels of a given potential to levels of either the same or another potential, subject to rotational selection rules specified by the user.
  6. Moreover, the complete program includes a package of potential-generating routines which can be used to interpolate over and extrapolate beyond a given set of potential points, or to generate a potential from a range of analytic functions. However, the one supplied also may be readily replaced by a user-supplied potential generating subroutine.

This Link has been superceded by the 'LEVEL16' Link accessed via the 'Computer Programs' link on with my top level www page leroy.uwaterloo.ca where you will find assess to an updated (as of August 2016) version of the code and manual.

Site owned by R.J. Le Roy: leroy @ UWaterloo.ca

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