Coulomb potential at any desired point in the cell can be calculated here employing point charges on atoms specified manually. The Ew-menu:
..............MENU for Madelung potential ...........
......... Change these parameters if necessary: .....
1. Point of interest (Angstroms): ( 0.05194, 0.05194, 0.03418)
Point of interest (fractionl): ( 0.00477, 0.00477, 0.00314)
3. Charges on species: KNOWN
4. Charges on ions: KNOWN
Ok. Adopt present setting and calculate the potential <- Done!
>>>> Madelung potential: -.195715E-02
------- g e n e r a l s e t t i n g s --------
2. Charges on all species are the same: YES
An. [For input] Coordinates are specified in: <AtomNumber>
Co. Show current atomic positions in fractional/Cartesian
Sy. Show the point symmetry
Ew. Ewald constant: 0.162885E+00
5. Precision of the summations: 0.100000E-09
6. Multiplication factor: 0.100000E+01
Vb. Verbose: NO
Q. Quit: skip the step and do NOT proceed.
---> Choose the item and press ENTER:
First, specify charges on atoms (options 3 and 4). It is either possible to do it separately for every atom in the cell or only for different species (setting 2). Then, choose the point where the potential is to be calculated (option 1). The Ewald constant is chosen using a special algorithm; however, it can be changed. Finally, the potential is calculated using Ok. A file madel.dat is produced with all the results of the calculation.