## CLstunfti: An extendable Python toolbox to compute scattering of electrons with a given kinetic energy in liquids and amorphous solids

#### Description

CLstunfti is an extendable Python toolbox to compute scattering of electrons with a given kinetic energy in liquids and amorphous solids. It uses a continuum trajectory model with differential ionization and scattering cross sections as input to simulate the motion of the electrons through the medium.

Originally, CLstunfti was developed to simulate two experiments: A measurement of the effective attenuation length (EAL) of photoelectrons in liquid water [1] and a measurement of the photoelectron angular distribution (PAD) of photoelectrons in liquid water [2]. These simulations were performed to determine the elastic mean free path (EMFP) and the inelastic mean free path (IMFP) of liquid water [3].

#### Practical application

The EMFP and IMFP are two central theoretical parameters of every simulation of electron scattering in liquids, but they are not directly accessible experimentally. As CLstunfti can be used to determine the EMFP and IMFP from experimental data, and as it can be easily extended to simulate other problems of particle scattering in liquids, it was decided to make the source code publicly available. For this purpose, within the E-CAM module, the necessary steps were taken to make CLstunfti a useful toolbox for other researchers by providing a documentation, examples, and also extensive inline documentation of the source code.

#### Source code

CLstunfti is available at https://gitlab.com/axelschild/CLstunfti .

#### References

[1] Suzuki, Nishizawa, Kurahashi, Suzuki,*Effective attenuation length of an electron in liquid water between 10 and 600 eV*, Phys. Rev. E 90, 010302 (2014) [2] Thürmer, Seidel, Faubel, Eberhardt, Hemminger, Bradforth, Winter,

*Photoelectron Angular Distributions from Liquid Water: Effects of Electron Scattering*, Phys. Rev. Lett. 111, 173005 (2013) [3] Schild, Peper, Perry, Rattenbacher, Wörner,

*A*

*lternative approach for the determination of mean free paths of electron scattering in liquid water based on experimental data*, J. Phys. Chem. Lett., 11, 1128−1134 (2020)