First-order MP2 molecular properties in a relativistic framework

The first implementation of analytical first-order one-electron molecular properties at the Dirac-Coulomb MP2 level of theory is described. The formalism presented allows for the use of inactive spinors. The method has been applied to the calculation of parity violation energies in H2X2 (X = O, S, Se, and Te). Electron correlation does not play an important role for this property in this kind of systems, but the effect is shown to be very geometry dependent. (C) 2004 Elsevier B.V. All rights reserved.