ISSN:
0020-7608
Keywords:
autocorrelation function
;
optical potential
;
Lanczos algorithm
;
ozone photodissociation
;
hyperspherical coordinates
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
We present an L2 method aimed at directly computing autocorrelation functions 〈Φ0|Φt〉 for systems displaying long time recurrences. By making use of a Lanczos scheme, as previously proposed by Wyatt [Chem. Phys. Lett. 121, 301 (1985)], the method avoids explicit time propagation of the wavefunction. The problem associated with spurious recurrences, due to the finite size of the L2-box, is solved in terms of an optical potential located in the asymptotic region. The resulting complex representation of the Hamiltonian operator is handled by a complex symmetric Lanczos scheme, which retains the same basic advantages as its real version. The method is illustrated on the ozone photodissociation process which displays a very detailed recurrence structure over a long time period. It is shown that such a direct calculation of the correlation function is about one order of magnitude faster than an actual wavepacket propagation. The accuracy of the method is assessed by comparison to calculations performed without any optical potential but using a very large box size along the dissociation coordinate. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 68: 317-328, 1998
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
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