A new local density functional approach for the calculation of correlation energies of many-electron atomic systems is proposed by using the exact results for the correlation energy of a two-electron system bound by a harmonic oscillator external potential. This is motivated by the fact that the cor
Application of second-order density functional methods to the calculation of the BeFH potential energy surface
✍ Scribed by Alfredo Aguado; Virgilio Sanz; Miguel Paniagua
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 238 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0020-7608
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✦ Synopsis
Second-order density functional methods where the correlation energy depends on the . second-order density matrix and on a density functional are used to introduce the Ž . electron correlation in two-configuration direct minimization TCDM ab initio electronic Ž . energy calculations of three-dimensional potential energy surfaces PES . We analyzed the behavior of these methods in PES calculations by applying them to the Be q FH reaction. This system was studied also by the usual techniques, allowing a full comparison for the lowest 1 A X adiabatic state. In particular, we compared the results obtained using the TCDM and multiple reference single and double excitations configuration interaction Ž . Ž . MRDCI methods with the corresponding results obtained using the Colle᎐Salvetti CS Ž . and Moscardo᎐San Fabian MSF procedures, within the correlation factor method, using ´ás starting point the TCDM results. We found that the CS and MSF results are in a good overall agreement with the more accurate ab initio results, including the heights of the saddle points and the transition state.
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