ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
We present a theoretical and numerical comparison between two DIIS algorithms to which we refer herein as C1-DIIS and C2-DIIS. The C2-DIIS algorithm is shown to be equivalent to the traditional C1-DIIS algorithm near convergence and more stable numerically as regards the accumulation of round-off error when the C1-DIIS equations become (nearly) singular. The C2-DIIS algorithm also offers alternative solutions to the DIIS equations when anharmonicities or numerical difficulties are problematic. These properties of the C2-DIIS algorithm allow the use of much larger DIIS spaces, obviating the need for truncation of the DIIS space, which, when done, usually results in a loss of information contained in the iterated subspace. The C2-DIIS method can be considered to be a variant of the singular value decomposition method. © 1993 John Wiley & Sons, Inc.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560450106
