Details

Autor(en) / Beteiligte

• Lehoucq, R.B.
• Gray, S.K.
• Zhang, D.-H.
• Light, J.C.

Titel

Vibrational eigenstates of four-atom molecules: a parallel strategy employing the implicitly restarted Lanczos method

Ist Teil von

• Computer physics communications, 1998-03, Vol.109 (1), p.15-25

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

1998

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• We present an approach for determining the vibrational eigenstates of four-atom molecules. The primary representation of the (six-dimensional) eigenstates involves a finite basis or quantum number representation, whereas Hamiltonian matrix-vector products are evaluated with the aid of certain grid or discrete variable representations. This approach leads to computational and memory demands that are within acceptable limits. The implicitly restarted Lanczos method, as implemented in the ARPACK suites of codes, is then applied to determine some of the corresponding vibrational eigenstates. A distributed-memory parallel implementation of the method allows very large symmetric matrix eigenvalue problems — on the order of N = 2 × 10 6 — to be tackled. The lowest fifty vibrational states of the HOCO molecule, with zero total angular momentum and even parity, are accurately computed on Argonne National Laboratory's IBM SP computer.