<div dir="ltr">Hi all,<br><br>I am using DFT+U to relax a defective surface system. 
Specifically, I am using theDFT+U method MULLIKENn. However, the following warning appears when 
computing:<br><br>*** 04:19:11 WARNING in dft_plus_u:mulliken :: DFT+U energy contibution ***<br> *** is negative possibly due to unphysical Mulliken charges. Check your ***<br> *** input, if this warning persists or try a different method!    <br>- I try to converge the initial SCF run with U=0eV firstly and then 
try to restart with DFT+U. but <span id="result_box" class="short_text" lang="en"><span class="hps">the same</span> <span class="hps">problem</span> <span class="hps">appears.</span></span><br>- Using U_RAMPING [eV] 0.1 and INIT_U_RAMPING_EACH_SCF did not help.<br>............<br>    &KIND Zn<br>    BASIS_SET DZVP-MOLOPT-SR-GTH<br>    POTENTIAL GTH-PBE-q12 <br>     &DFT_PLUS_U<br>        EPS_U_RAMPING 1.0E-3<br>        U_MINUS_J [eV] 2.0<br>        L 2<br>        U_RAMPING [eV] 0.7<br>      &END DFT_PLUS_U<br>   &END KIND<br>..................................<br>Thanks a lot for the attention,<br>best regards,<br></div>