Abstract
The efficacy of a method based on the direct inversion in the iterative subspace (DIIS) in accelerating the approach to self consistency in the calculation of theMCSCF wavefunction using a novel algorithm developed earlier, is compared with that of a simple damping technique. Although the ‘damping’ turns out to be ineffective in the ‘quadratic region’, it accelerates remarkably in the rate of descent on the energy hypersurface in the early stages of the iterative process which leads to an impressive overall increase in the rate of approach to self consistency. TheDIIS based procedure turns out to be ineffective when coupled to the present method and is plagued by ill conditioning problems. Calculations are done to compute the equilibrium geometrical parameter, charge density on different atoms, and dipole moment of HNO molecule in the lowest1,3 nπ* states at theINDO/2-MCSCF level.
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Adnan S S Z, Bhattacharyya S P and Mukherjee D, 1978Int. J. Quantum Chem. 14 289
Bhattacharyya S P and Mukherjee D 1979Chem. Phys. Lett. 66 511
Bhattacharyya S P and Mukherjee D 1981Int. J. Quantum Chem. 20 1165
Bhattacharyya S P, Mukherjee D, Bhattacharyya, D M and Khan P 1982Int. J. Quantum Chem. 22 753
Bruna P J and Marian C M 1979Chem. Phys. Lett. 67 109
Clementi E and Veillard A 1967Theor. Chim. Acta 7 133
Császár P and Pulay P 1984J. Mol. Struct. 114 31
Dalbey F W 1958Can. J. Phys. 36 1336
Das K K, Bhattacharyya S P and Mukherjee D 1986Int. J. Quantum Chem. (to be published)
Das K K, Mukherjee D, Bhattacharyya S P, Bhattacharyya D M and Khan P 1984Int. J. Quantum Chem. 25 809
Das G and Wahl A C 1967J. Chem. Phys. 47 2934
Hartree D R and Seirles B 1939Philos. Trans. R. Soc. A238 229
McWeeny R 1955Proc. R. Soc. London A232 114
McWeeny R 1956Proc. R. Soc. London A235 496
McWeeny R 1960Rev. Mod. Phys. 32 335
McWeeny R and Newbould L M 1980Mol. Phys. 39 353
Mukherjee D 1978Proc. Indian Acad. Sci. A87 37
Momura O 1980Int. J. Quantum Chem. 18 143
Olsen J and Yeager D L 1983 inAdvances in chemical physics (New York: John Wiley and Sons) vol. 54, pp. 1–176, and references therein
Pulay P 1980Chem. Phys. Lett. 73 393
Pulay P 1982J. Comput. Chem. 3 556
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Dedicated to Professor Sadhan Basu on the occasion of his 65th birth anniversary
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Das Kumar, K., Mukherjee, D. & Bhattacharyya, S.P. Applications of a novel algorithm for the calculation ofMCSCF wavefunction: a look into possible avenues of convergence acceleration. Proc. Indian Acad. Sci. (Chem. Sci.) 96, 135–143 (1986). https://doi.org/10.1007/BF02974146
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DOI: https://doi.org/10.1007/BF02974146