At the present time these programs are restricted to systems consisting of two spherically symmetric systems.
The primary data for all calculations consist of the pseudo-oscillator strength data files. These are constructed so that the excitation energy and oscillator strengths for the lowest couple of excitations closely correspond to those of the physical state. A pseudo-oscillator strength distribution was then used to incorporate the remainder of the higher valence and continuum excitations.
Data files for dynamic polarizabilities for 40 and 50 point quadrature grids are stored here. These are relatively simple ASCII data files. These are constructed so that the excitation energy and oscillator strengths for the lowest couple of excitations closely correspond to those of the physical state. A pseudo-oscillator strength distribution was then used to incorporate the remainder of the higher valence and continuum excitations.
dynamic.f computes the dynamic polarizability at imaginrary frequencies. This is a Fortran program that reads the pseudo-oscillator strength data and computes the dynamic polarizabilities at imaginary frequencies. The size of the grid can be set by the user. Using another transformation besides that built into the program is also possible by replacing the short subroutines that compute the integration points and weight factrs. The grid used in the Derevianko et al tabulations (2010 At. Data. Nucl. Data Tables 96 323) is already built into the program and it is transparent to use it to replace the existing transformation.
The program also outputs to a data file the quadrature grid for the frequency integration. This program also computes C3 for the atom and C6, C8 and C10 for the homonuclear dimer. The dispersion parameters are computed using the pseudo-state expansion and the polarizability integrals and compares them. This provides an automatic check of the integration grid.
Instructions on running this program can be found in the comments embedded in the Fortran program itself.
sumrule.f is a program designed to compute dispersion parameters using oscillator strength sum rules. For this program, one simply copies data file-1 to input file-1, copies data file-2 to input file-2, then just runs the program. and the dispersion coefficients for that pair of atoms is computed.
The dispersion coefficients are written to screen output (unit 6). Instructions on running the programs can be found in the comments embedded in the Fortran program itself.
casimir.f uses the dynamic polarizabilities to compute the dispersion parameters using the Casimir-Polder inetgral. This is reliant on having all the dynamic polarizabilities computed on the same frequency grid. All dynamic polarizabilities available on this web-site have been computed for use with the same quadrature rule. One of the data file inputs for this program is the table of integration points and weights.
However, there may be cases where the dynamic polarizability might be best computed with a another frequency grid. In these cases, it is possible to construct the dynamic polarizability on a different grid by editing Program 1. The grid used in the Derevianko et al tabulations (2010 At. Data. Nucl. Data Tables 96 323) is already embedded into the program.
The operation of this program is similar to sumrule.f. First of all, one simply copies data file-1 to input file-1, copies data file-2 to input file-2. Then one just copies the file containing the quadrature rule definition to the appropriate input file name. The dispersion coefficients are written to screen output (unit 6).
Instructions on running this program can be found in the comments embedded in the Fortran program itself.
| Return Links | |
|---|---|
| Van der Waals home page | |
| CDU home page |