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

Sergei Adamson; Andrei Zaitsevskii; Andrei Dement'ev; Nicolai Stepanov

doi:doi:10.1051/jp2:1997132

Numéro		J. Phys. II France Volume 7, Numéro 3, March 1997


Page(s)		393 - 399
DOI		https://doi.org/10.1051/jp2:1997132

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)

Abstract
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.