Relativistic Dirac–Fock calculations for closed‐shell molecules

A new code has been written to perform relativistic Dirac–Fock self‐consistent field (SCF) calculations on closed‐shell molecules of any symmetry. The choice of the basis set allows us to work at different levels of approximation depending on the precision required. Calculations on the H 2 Po molecule show that accurate results on specific problems like geometry optimization can be obtained by evaluating the two‐electron integrals on half the basis spinors.