Energy deposition in SO2 via intense infrared laser multiphoton excitation

Hamiltonian description and 6D calculations on the ammonia vibrational levels

“…The method is nonperturbative and based on the well known AI search procedure, developed and mainly applied for large scale calculations on highly excited vibrational states in polyatomic molecules [42][43][44][45][46][47]. The efficiency of our vibrational method is essentially based on the availability of a completely symmetrized, separable (in product form), unrestricted vibrational basis set |iae (Eq.…”

Iterative eigenvalue method using the Bloch wave operator formalism with Padé approximants and absorbing boundaries

“…The important task is that of choosing the dimension N 0 of the model space S 0 and the mode of construction of S 0 around an initial unperturbed state ͉i͘. Various approaches to a suitable definition of S 0 have been proposed in the literature; these include the adiabatic reduced coupled equation method [30], the low-frequency expansion method [31], and several artificial intelligence techniques [32][33][34]. In our approach we use an algorithm based on the wave operator formalism.…”

Effective Hamiltonian Theory and Molecular Dynamics

“…Equation 17has the advantage over eq. (18) of showing clearly that the wave operator is a non-unitary and non-singular transformation (T = 1 + X) which possesses a trivial inverse (T ?1 = 1 ? X) 31] (see g.1).…”

“…The vectors belong to a subspace of relatively small dimension, which is usually called the active space (A.S) The literature o ers various formulations for selecting these active spaces and for projecting the quantum dynamics into them. Probably the best known approaches are arti cial intelligence techniques 16,17,18] for subspace selection and the recursive residue generation method 19], in which transition amplitudes are computed from a recursive calculation which uses the Lanczos algorithm to give the residues and poles of several Green's functions.…”