Examples of programs written with IRPF90 (french version)

The preprocessor irpf90 is a tool for programming efficiently in FORTRAN90; it is distributed via SourceForge.
The author is Anthony Scemama (IRSAMC Toulouse). However, the idea is much older, developed by François Colonna and implemented initially under the name OSIPE (reference: F. Colonna, L.-H. Jolly, R. A. Poirier, J. Angyan, G. Jansen ``OSIPE: A tool for scientific programming in FORTRAN'', Comp.Phys.Commun. 81 (1994) 293-317).

Implicit reference of parameters (IRP): instead of 1) transmitting a list of arguments, of 2) repeating definitions of parameters, or 3) explicit allocations of arrays in memory, a construction of the form

BEGIN_PROVIDER [type, name, (dimension)]
END_PROVIDER

defines a desired structure or object, which may be compiled into code. The preprocessor detects the order of construction of different structures, and verifies avalability and coherence upon compilation. From the different blocks of ``providers'' (extension .irp.f) a complete source of F90 code is produced, together with a ``Makefile'' and a list of dependencies. As well, cross-referencing in a man-page style of the defined objects and subroutines is available via a command ``irpman''.

Here are some examples of small codes (tar.gz with Makefile and sources, needing gfortran):

The Syracuse theorem (with intermediate files)
The Babylonian root R=(R+S/R)/2
Visualization of a matrix
Clebsch-Gordan vector recoupling coefficients
Cartesian expansion coefficients of real solid harmonics (with intermediate files)
The Slater atomic model
Slater rules for matrix elements of the Hamilton matrix in the basis of excited determinants
A 1D Hueckel program (you need the RS routine from eispack)
Calculation of the pH of a multi-acid, iterative procedure
Implementation of GUGA for generating a CAS space from the number of electrons, number of orbitals and total spin
Transformation of a Gaussian fchk to a wfn file
Example of parallelization with MPI
Molecular vibrational frequencies and modes from atomic densities (together with the data files)
Convolution of discrete data with a Gaussian

Finding roots of a polynomial (Newton + polynomial division )
Transformmation of QChem input to Molpro input for segmented systems)
Creation of minimal Slater (H-3) basis set from a set of exponents, see I.V. Popov, A.L. Tchougréeff, Theor.Chem.Acc., 138 (2019) 9
A Sudoku solver

These programs may be distributed free of charge.