title: Electronic structure and chemical bonding in the lowest electronic states of TcN.
abstract: Multiconfiguration second-order perturbation theory, with the inclusion of relativistic effects and spin-orbit coupling, was employed to investigate the nature of the ground and low-lying Lambda-S and Omega states of the TcN molecule. Spectroscopic constants, effective bond order, and potential energy curves for 13 low-lying Lambda-S states and 5 Omega states are given. The computed ground state of TcN is of Omega = 3 symmetry (R(e) = 1.605 A and omega(e) = 1085 cm(-1)), originating mainly from the (3)Delta Lambda-S ground state. This result is contrasted with the nature of the ground state for other VIIB transtion-metal mononitrides, including X(3)Sigma(-) symmetry for MnN and Omega = 0(+) symmetry for ReN, derived also from a X(3)Sigma(-) state.
authors.affiliation: Instituto de Química, Universidade de São Paulo, SP, Brazil. ancborin@iq.usp.br
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Borin
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Gobbo