Lead references
E. van Lenthe, E.J. Baerends and J.G. Snijders, Relativistic regular two-component Hamiltonians. Journal of Chemical Physics 99, 4597 (1993)
E. van Lenthe, E.J. Baerends and J.G. Snijders, Relativistic total energy using regular approximations. Journal of Chemical Physics 101, 9783 (1994)
E. van Lenthe, A.E. Ehlers and E.J. Baerends, Geometry optimization in the Zero Order Regular Approximation for relativistic effects. Journal of Chemical Physics 110, 8943 (1999)
Suggested related references
E. van Lenthe, J.G. Snijders and E.J. Baerends, The zero-order regular approximation for relativistic effects: The effect of spin.orbit coupling in closed shell molecules. Journal of Chemical Physics 105, 6505 (1996)
E. van Lenthe, R. van Leeuwen, E.J. Baerends and J.G. Snijders, Relativistic regular two-component Hamiltonians. International Journal of Quantum Chemistry 57, 281 (1996)
