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A note on density matrix extrapolation and multiple solutions of the unrestricted Hartree–Fock equations

✍ Scribed by P. G. Mezey; O. P. Strausz; R. K. Gosavi

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
266 KB
Volume
1
Category
Article
ISSN
0192-8651

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✦ Synopsis

Abstract

Unrestricted Hartree–Fock (UHF) SCF–MO calculations on the doublet reaction surface for the addition of methylidyne (CH) to ethylene (C~2~H~4~) using the standard extrapolation techniques of the GAUSSIAN 70 program show erratic behavior. On the other hand, the potential energy surface calculated without extrapolation of the density matrix and by using the final density matrix of a neighboring point as the initial guess for the density matrix for the new point gave a smooth potential curve without any kinks or erratic pattern. Therefore, the density extrapolation technique should be used with particular caution in UHF calculations.

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