<p>Hello CP2K community,</p><p>I am calculating the bulk AlN band gap using CP2K 2024.1 with HSE, ADMM, a 72-atom 3x3x2 wurtzite supercell, and Gamma point sampling. My target band gap is approximately 6.1 eV.</p><p>Using standard diagonalization, Broyden mixing, ADMM_PURIFICATION_METHOD NONE, and alpha=0.15, I obtained a converged gap of:</p>Band gap = 5.267211 eV
<p>However, when I used alpha=0.20, the SCF initially approached about 5.7 eV but later diverged catastrophically. A retry with DIRECT_P_MIXING and a level shift produced a NaN in the first SCF step.</p><p>Could you please advise: What is the recommended stable procedure or strategy so that the calculated bandgap reaches 6.1 eV using HSE calculations with ADMM? </p><p>Any guidance would be greatly appreciated.</p><p>Thank you.</p>

<p></p>

-- <br />
You received this message because you are subscribed to the Google Groups "cp2k" group.<br />
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>.<br />
To view this discussion visit <a href="https://groups.google.com/d/msgid/cp2k/4d47782f-5994-47fa-9366-63bda159a137n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/4d47782f-5994-47fa-9366-63bda159a137n%40googlegroups.com</a>.<br />