Organisation of the optimisation

Reading of experimental data Is done with a subroutine RDEXP, which Is called once per job. It runs over the molecules, and for each molecule It runs over the types of observables The following data are read The list number of each Internal coordinate, rotational constant, atomic charge, dipole moment (always 1) and Internal frequency on which optimisation is desired its experimental value its experimental uncertainty. The uncertainty may be left out if so, it is given a standard value. This is practical for frequencies  

The routine counts the number of data of each type for each molecule and the total number of data All the information is stored in a background file  

The programme OPTIM controls the optimisation. Through calls of a subroutine NPAR it changes by small amounts the values of those parameters that are to be optimised, one by one, and through subroutine BUILDZ the elements of the Z matrix are built up, one row per parameter to be optimised The rows are written on a background 

The Z matrix is put together from its rows by a subroutine ZMATRX, and is printed for inspection, one set of lines of elements per parameter to be optimised. 

The WAy vector is constructed by a subroutine BUILDY, which has access to the background file of experimental data and to files of calculated observables prepared during the current optimisation cycle. 

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