1. Robert Thiele, Sang-Kil Son, Beata Ziaja, and Robin Santra, “Effect of screening by external charges on the atomic orbitals and photoinduced processes within the Hartree-Fock-Slater atom,” Phys. Rev. A 86, 033411 (2012).
2. Beata Ziaja, Zoltan Jurek, Nikita Medvedev, Sang-Kil Son, Robert Thiele, and Sven Toleikis, “Photoelectron spectroscopy method to reveal ionization potential lowering in nanoplasmas,” J. Phys. B: At. Mol. Opt. Phys. 46, 164009 (2013) [special issue on frontiers of free-electron laser science].
3. Sang-Kil Son, Robert Thiele, Zoltan Jurek, Beata Ziaja, and Robin Santra, “Quantum-mechanical calculation of ionization potential lowering in dense plasmas,” Phys. Rev. X 4, 031004 (2014).
4. Malik Muhammad Abdullah, Anurag, Zoltan Jurek, Sang-Kil Son, and Robin Santra, “Molecular-dynamics approach for studying the nonequilibrium behavior of x-ray-heated solid-density matter,” Phys. Rev. E 96, 023205 (2017).
5. John Jasper Bekx, Sang-Kil Son, Beata Ziaja, and Robin Santra, “Electronic-structure calculations for nonisothermal warm dense matter,” Phys. Rev. Res. 2, 033061 (2020).
6. Rui Jin, Malik Muhammad Abdullah, Zoltan Jurek, Robin Santra, and Sang-Kil Son, “Transient ionization potential depression in nonthermal dense plasmas at high x-ray intensity,” Phys. Rev. E 103, 023203 (2021).
7. Rui Jin, Zoltan Jurek, Robin Santra, and Sang-Kil Son, “Plasma environmental effects in the atomic structure for simulating x-ray free-electron-laser-heated solid-density matter,” Phys. Rev. E 106, 015206 (2022).
8. Stanislaw Wirok-Stoletow, Rui Jin, Daria Kolbasova, Sang-Kil Son, Andrew Aquila, and Robin Santra, “Nonsequential two-photon absorption in solid Ge irradiated by an intense x-ray free-electron-laser pulse,” Phys. Rev. A 106, 023118 (2022).