ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The usefulness of the muffin-tin (MT) Xα method for computing potential energy curves of molecules containing transition metal atoms is investigated using TiF4 as a test case. Two previously suggested improvements to the MT calculation of the total energy—optimization of the MT sphere radii and the "nonmuffin-tin'' (NMT) correction of Connolly and Danese—are studied. To facilitate the optimization of sphere radii, a formula for the derivative of the total energy with respect to these radii is derived, and its accuracy tested. Procedures for choosing sphere radii are discussed and calculations of the a1 symmetric stretch potential energy surface are performed to compare the results of optimizing the sphere radii with those of the commonly used Norman method of choosing radii. It is found that optimization does not greatly improve the calculated equilibrium bond length, vibrational frequency, or dissociation energy. The inclusion of the NMT correction, however, does lead to a bond length and vibrational frequency in good agreement with experiment. The frequency of the t2 stretching vibration is also calculated using the NMT correction, but here the agreement with experiment is less good.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.459109
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