According to the cp2k manual, there is a ALPHA keyword in the Ewald input section (Section path: <a href="https://manual.cp2k.org/trunk/CP2K_INPUT.html">CP2K_INPUT</a> / <a href="https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL.html">FORCE_EVAL</a> / <a href="https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/DFT.html">DFT</a> / <a href="https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/DFT/POISSON.html">POISSON</a> / <a href="https://manual.cp2k.org/trunk/CP2K_INPUT/FORCE_EVAL/DFT/POISSON/EWALD.html">EWALD</a>). I am not 100% sure about the meaning of ALPHA, but my gut feeling is that ALPHA controls the real space part of the Ewald summation. But as I was going through the cp2k code (specifically the qs_ks_build_kohn_sham_matrix subroutine), I did not find the code that handles the real space part of the Ewald summation. It seems to me that all the Ewald summation are included in the k-space summation. The recent JCP(2020) paper on CP2K suggests that too. So is ALPHA an obsolete parameter? -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>. To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/8cb6666b-326a-40d2-a5a6-734e38eb4451n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/8cb6666b-326a-40d2-a5a6-734e38eb4451n%40googlegroups.com</a>.