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402. IDEM: A Program to Construct an Idempotent First-
Order Density Matrix from One-Electron Properties
by George A. Henderson and Francis C. Myer, Department of Physics, Southern Illinois University, Edwardsville, Illinois 62026 These routines enable one to determine an idempotent first-order density matrix from one-electron expectation values, given the matrix representatives of the corresponding one-electron operators in a finite basis. The method of Clinton et al.1 is used, and various convergence-improvingtechniquesand computational refinements2,3 are implemented. Among possible uses of the program are constrained SCF calculations3, fitting an accurate calculation to a small basis using the accurate expectation values4, and constructing an idempotent density (and thence a single-determinant wavefunction and its energy) from experimental density data, such as x-ray scattering results.5-7 References: 1. W.L. Clinton, A.J. Galli and L.J. Massa, Phys. Rev., 177, 7 (1969). 2. W. L. Clinton, A. J. Galli, G. A. Henderson, G. B. Lamers, L. J. Massa and J. Zarur, Phys. Rev., 177, 27 (1969). 3. G. A. Henderson and R. K. Zimmerman, Jr., J. Chem. Phys., 65, 619 (1976). 4. W. L. Clinton and G. B. Lamers, Phys. Rev., 177, 19 (1969). 5. W. L. Clinton and L. J. Massa, Phys. Rev. Lett., 29, 1363 (1972). 6. W. L. Clinton, C. A. Frishberg, L. J. Massa and P. A. Oldfield, Int. J. Quantum Chem. Symp., 7, 505 (1973). 7. G. A. Henderson, Int. J. Quant. Chem., 13, 143 (1978). FORTRAN IV (IBM 360/370) Lines of Code: 2700 Recommended Citation: G. A. Henderson and F. C. Myer, QCPE 13, 402 (1981). |