<div dir="ltr">Hi Matthias, the MOM method is simply an alternative way to occupy atomic orbitals during SCF iterations. An excited state that you are trying to handle by using the MOM protocol should preserve the number of electrons for every spin channel from the ground state calculation of the given multiplicity. In your specific case (a methane cation with its beta electron being excited from the 1st orbital into the 5th orbital) you can achieve this by running a conventional ground state DFT calculation for a methane cation first: &DFT CHARGE 1 MULTIPLICITY 2 &SCF SCF_GUESS atomic # need this for the subsequent MOM calculation ADDED_MOS 10 EPS_SCF 1.0E-7 MAX_SCF 50 &END SCF ... &END DFT Then you can setup the MOM calculation by adding the MOM section under your SCF section. You need to use the molecular orbitals obtained at the previous step as an initial guess for you MOM run: &DFT CHARGE 1 MULTIPLICITY 2 &SCF SCF_GUESS restart ADDED_MOS 10 WFN_RESTART_FILE_NAME methane_cation.wfn EPS_SCF 1.0E-7 MAX_SCF 50 &MOM DEOCC_BETA 1 OCC_BETA 5 &END MOM &END SCF ... &END DFT It may also be useful to print the actual occupation numbers of the molecular orbitals to be sure that your system stays at the desired excited state during the wavefunction optimisation. &DFT ... &PRINT &MO EIGENVALUES OCCUPATION_NUMBERS &END MO &END PRINT ... &END DFT If it is not the case, try to decrease the ALPHA parameter under the mixing section: &SCF ... &MIXING ALPHA 0.10 &END MIXING ... &END SCF Upon convergence CP2K saves the excited-state wavefunction into the restart file. If you plan to do anything on top of it -- for example, to run a molecular dynamics simulation for the molecule in this particular excited state -- you need to set up you calculation and simply add an empty MOM section under the SCF section. Reoccupation of the molecular orbitals is not needed in this case because the wavefunction, which is going to be read from the restart file, already corresponds to the target excited state. Hope this helps, Sergey On Monday, June 11, 2018 at 7:25:47 PM UTC+1, Matthias wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr"><div>Hi,</div><div> </div><div>I am struggling to figure out, how to correctly use the MOM method to specify that the carbon atom in methane should have a core hole, i.e. to remove one core electron from the system. When I use the following input, the program crashes with a segmentation fault. However, since I ran the test on the UK national supercomputer Archer using the default version of CP2K, I would be surprised if it were compiled incorrectly, + I have been able to run other calculations with no problems on the same system. The ground state calculation with the same basis set runs smoothly in no time at all.</div><div> </div><div>Any help would be greatly appreciated.</div><div> </div><div>Best Regards,</div><div> </div><div>Matthias</div><div> </div><div>P.S. I am aware that a similar question has been asked before, but since it didn't receive any responses I thought I should start a new one. <a href="https://groups.google.com/forum/#!searchin/cp2k/mom%7Csort:date/cp2k/JVKa3FqbUS0/_O-xtwgZAgAJ" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/forum/#!searchin/cp2k/mom%7Csort:date/cp2k/JVKa3FqbUS0/_O-xtwgZAgAJ';return true;" onclick="this.href='https://groups.google.com/forum/#!searchin/cp2k/mom%7Csort:date/cp2k/JVKa3FqbUS0/_O-xtwgZAgAJ';return true;">https://groups.google.com/forum/#!searchin/cp2k/mom%7Csort:date/cp2k/JVKa3FqbUS0/_O-xtwgZAgAJ</a> </div><div> </div><div> </div><div>&GLOBAL PROJECT methane RUN_TYPE ENERGY PRINT_LEVEL MEDIUM &END GLOBAL &FORCE_EVAL METHOD Quickstep &DFT &POISSON PERIODIC NONE PSOLVER WAVELET &END POISSON &QS METHOD GAPW &END QS CHARGE 1 MULTIPLICITY 2 LSD &SCF MAX_ITER_LUMOS 10000 EPS_SCF 1.0E-6 SCF_GUESS ATOMIC MAX_SCF 60 EPS_LUMOS 0.000001 &OUTER_SCF EPS_SCF 1.0E-6 MAX_SCF 6 &END &MOM DEOCC_BETA 1 PROJ_FORMULA SUM &END MOM &END SCF &XC &XC_FUNCTIONAL PBE &END XC_FUNCTIONAL &END XC &END DFT &SUBSYS &CELL ABC 10 10 10 PERIODIC NONE &END CELL &TOPOLOGY &CENTER_COORDINATES &END &END &COORD C 0.00000010 -0.00000174 0.00000062 H 0.97867541 0.00000198 0.49253941 H 0.00648797 0.72060111 -0.82527843 H -0.77313050 0.28064054 0.72381230 H -0.21202870 -1.00124727 -0.39108047 &END COORD &KIND H &BASIS 6 1 0 0 4 1 0.754732D+02 0.427821D-02 0.113575D+02 0.328672D-01 0.260081D+01 0.159578D+00 0.735503D+00 0.500000D+00 1 0 0 1 1 0.231761D+00 1.0000000 1 0 0 1 1 0.741675D-01 1.0000000 1 1 1 1 1 0.160000D+01 1.0000000 1 1 1 1 1 0.450000D+00 1.0000000 1 2 2 1 1 0.125000D+01 1.0000000 &END POTENTIAL ALL &POTENTIAL 1 0 0 0.20000000 0 &END &END KIND &KIND C &BASIS 17 1 0 0 7 1 0.272316E+08 0.979800E-06 0.108927E+07 0.441346E-04 0.871412E+05 0.784056E-03 0.130520E+05 0.639707E-02 0.297061E+04 0.333869E-01 0.841460E+03 0.140202E+00 0.274589E+03 0.500000E+00 1 0 0 1 1 0.992150E+02 1.0000000 1 0 0 1 1 0.386940E+02 1.0000000 1 0 0 1 1 0.159109E+02 1.0000000 1 0 0 1 1 0.676677E+01 1.0000000 1 0 0 1 1 0.289837E+01 1.0000000 1 0 0 1 1 0.822020E+00 1.0000000 1 1 1 3 1 0.963557E+03 0.290977E-02 0.148240E+03 0.568381E-01 0.349117E+02 0.500000E+00 1 1 1 1 1 0.108936E+02 1.0000000 1 1 1 1 1 0.419336E+01 1.0000000 1 1 1 1 1 0.171343E+01 1.0000000 1 1 1 1 1 0.735662E+00 1.0000000 1 0 1 1 1 1 0.323000E+00 1.0000000 1.0000000 1 0 1 1 1 1 0.123000E+00 1.0000000 1.0000000 1 2 2 1 1 0.520000E+01 1.0000000 1 2 2 1 1 0.135000E+01 1.0000000 1 2 2 1 1 0.520000E+00 1.0000000 &END POTENTIAL ALL &POTENTIAL 4 2 0 0.34883045 0 &END &BS &BETA L 0 N 1 NEL -2 &END BETA &END BS &END KIND &END SUBSYS &END FORCE_EVAL </div><div> </div><div> </div><div> </div><div> </div></div></blockquote></div>