J. Phys. II France
Volume 7, Numéro 3, March 1997
Page(s) 393 - 399
DOI: 10.1051/jp2:1997132
J. Phys. II France 7 (1997) 393-399

Multi-Partitioning QDPT and Difference-Dedicated CI Calculations of Non-Adiabatic Couplings: Application to Charge Transfer in LiF System

Sergei Adamson1, Andrei Zaitsevskii1, Andrei Dement'ev2 and Nicolai Stepanov1

1  Laboratory of Molecular Structure and Quantum Mechanics, Chemical Department, M. Lomonosov Moscow State University, 119899 Moscow, Russia
2  Inorganic Chemistry Department, Moscow State Pedagogical University, Nesvizhskii per., 119882 Moscow, Russia

(Received 2 May 1996, revised 9 October 1996, accepted 3 December 1996)

Potential energy and non-adiabatic coupling functions for the two lowest $^1\Sigma^+$ states of LiF were calculated using the recently proposed perturbative approach, based on the multiple partitioning of the full Hamiltonian, and the difference-dedicated CI method. The results are compared with MRDCI and available full CI data for the same AO basis set. A high accuracy was achieved with a semiempirical perturbative scheme combining the direct calculations at second order with an approximate estimation of higher-order local contributions.

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