Given the two sets of configuration lists, wave functions and
eigenvectors, biotr evaluates the transition data between
the two CI expansions,
,
with
representing a magnetic or electric
transition probability operator of any order.
The calculation is non-relativistic when the eigenvectors were obtained using the mchf method. In this case the program expects to find the eigenvectors in a file with a .l suffix. If the user had applied the relativistic corrections using the Breit-Pauli method, the transitions determined by biotr will include the relativistic effects as well. In this case the program expects to read the eigenvectors from a file with .j suffix. In biotr, the initial and final states, which may not be orthogonal, are transformed in such a way that the orbitals are orthogonal between states so that orthogonal methods may be used to evaluate the transition matrix elements [#!mrg-bio!#].