Use TCS/IDA option

In order to access this option you should select the EXPERT OPTIONS sheet (close to the upper left corner of the main program window).

For energies lower than 100 keV/u and for weakly bound valence electrons (specifically for conduction-band electrons), the UCA method is not accurate anymore. The TCS/IDA option allows for replacing the UCA calculations for the valence electrons by more accurate ones based on the free-electron-gas approximations IDA (Induced Density Approximation) and TCS (Transport Cross-Section), as described in Physical Review A, 94, 042704 (2016) and J. Phys. B At. Mol. Opt. Phys., 50,185201 (2017).

The input is the number of valence electrons Nval per atom. Default option is TCS otherwise IDA checkbox should be selected.

The program calculates the static screening using the FSR (Friedel sum rule) and uses an interpolation formula from J. Phys. B At. Mol. Opt. Phys., 50,185201 (2017) to get a velocity dependent dynamical screening. It has to be noted that while this procedure may be sufficient for calculations of stopping cross-sections, it does not provide a realistic impact-parameter-dependent energy loss.