Program betaFIT

betaFIT is a Fortran program for fitting a set of radial potential energy function values to an analytic functional form. The present version (Version 2.1) of this code can perform fits to four different types of analytic potential energy function: the Expanded Morse Oscillator (EMO) potential, the the Morse/Long-Range (MLR) potential, the Double Exponential/Long-Range (DELR) potential, and a wide variety of polynomial expansions including the Dunham, Simons-Parr-Finlan and Ogilvie-Tipping potentials, all of which may be described as particular types of Surkus' "Generalized Potential Energy Function" (GPEF).

The source code for Version 2.1 of program betaFIT and the associated user manual University of Waterloo Chemical Physics Research Report CP-666 (2013) are distributed free of charge. However, its use should be acknowledged by citation of the above report. This manual presents a brief summary of the computational methodology and a detailed description of the nature of the input data file and the options invoked by various input parameter choices. The FORTRAN source code is automatically distributed (by e-mail) to anyone who fill in the following form: Download betaFIT .

Caution ... compiling this code using an ifort compiler at any optimization level other than -g or -O0 seems to yield an unstable executable.

Updates to the code and manual since the release of Version 2.0 (June 2009) are listed here.

I would be pleased to receive information regarding apparent or real malfunctions of this code or weakness in the documentation. However, the program should be fairly robust, and is fairly extensively commented internally. If you encounter problems obtaining either the source code or a printed copy of the manual, please contact the author by e-mail. Queries regarding this program or its distribution should be addressed to R.J. Le Roy (519) 888-4051 or leroy @

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

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