1900.readme

     There are too many configurations to run at once with Cowan's 
program so some ions are run twice with different configurations.  
The limit is eight types of even or odd configurations.  The programs 
should be rewritten to allow sixteen.  

     Suffix Z or X includes all the low configurations below the first 
ionization limit plus low doubly excited configurations.  Suffix Y or 
W drops g, h, i, k, l configurations and adds high doubly excited 
configurations.  Since the configuration interactions are different, 
the predicted levels can have different energies.  The files *.gam can 
have different values.  The linelists have lines that can be duplicated
with different values.  Files without suffixes are produced by merging 
the suffix files and removing the duplicates.  

     In my version of Cowan's program the configurations are numbered 
with one character 1-9,A-Z,a-z up to 61.  The additional configurations 
in the Y or W files are numbered with symbols from the keyboard.  See 
the beginning of the *.gam files.  

     Most of the doubly excited levels are autoionizing.  Their widths
will have to be put in by hand if they are known.