<div dir="ltr">Hi, <div><br></div><div> I am trying to use MOM and I have some problems.</div><div>I start from a ground state closed-shell converged wavefunction, and I use the restart file for the MOM calculation. I just de-occupy the beta HOMO to occupy the LUMO beta. </div><div>The HOMO-LUMO gap of this system is around 2.0 eV, so there shouldnt be any problem to converge the excited state. </div><div>However, after a few iterations, when the DIIS kicks in, it immediately swaps to the ground state energy (E = -5725.1289....) .</div><div><br></div><div>
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<p class="p1"><span class="s1"> Step Update method Time Convergence Total energy Change</span></p>
<p class="p1"><span class="s1"> ------------------------------------------------------------------------------</span></p>
<p class="p1"><span class="s1"> 1 P_Mix/Diag. 0.40E+00 13.8 0.32547826 -5724.9981579203 -5.72E+03</span></p>
<p class="p1"><span class="s1"> 2 P_Mix/Diag. 0.40E+00 16.1 0.18145011 -5725.0429211687 -4.48E-02</span></p>
<p class="p1"><span class="s1"> 3 P_Mix/Diag. 0.40E+00 16.0 0.11353690 -5725.0753406595 -3.24E-02</span></p>
<p class="p1"><span class="s1"> 4 P_Mix/Diag. 0.40E+00 16.1 0.06733805 -5725.0961299910 -2.08E-02</span></p>
<p class="p1"><span class="s1"> 5 DIIS/Diag. 0.20E-02 16.1 0.04123847 -5725.1090261343 -1.29E-02</span></p>
<p class="p1"><span class="s1"> 6 DIIS/Diag. 0.11E-02 16.1 0.00192988 -5725.1289018949 -1.99E-02</span></p>
<p class="p1"><span class="s1"> 7 DIIS/Diag. 0.31E-03 16.1 0.00128342 -5725.1289258147 -2.39E-05</span></p>
<p class="p1"><span class="s1"> 8 DIIS/Diag. 0.28E-03 16.1 0.00032442 -5725.1289261285 -3.14E-07</span></p>
<p class="p1"><span class="s1"> 9 DIIS/Diag. 0.96E-04 16.1 0.00018951 -5725.1289310034 -4.87E-06</span></p>
<p class="p1"><span class="s1"> 10 DIIS/Diag. 0.45E-04 16.1 0.00004841 -5725.1289312796 -2.76E-07</span></p>
<p class="p1"><span class="s1"> 11 DIIS/Diag. 0.17E-04 16.1 0.00003119 -5725.1289314498 -1.70E-07</span></p>
<p class="p1"><span class="s1"> 12 DIIS/Diag. 0.11E-04 16.1 0.00001487 -5725.1289314674 -1.76E-08</span></p>
<p class="p1"><span class="s1"> 13 DIIS/Diag. 0.28E-05 16.1 0.00000367 -5725.1289314718 -4.34E-09</span></p>
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<p class="p1"><span class="s1"> *** SCF run converged in 13 steps ***</span></p></div><div><br></div><div>I tried to play with the alpha mixing parameter, with a EPS_DIIS tight (to avoid that the DIIS interfere) but no success:</div><div><br></div><div>
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<p class="p1"><span class="s1"> 1 P_Mix/Diag. 0.10E-03 13.8 0.32547826 -5724.9981579203 -5.72E+03</span></p>
<p class="p1"><span class="s1"> 2 P_Mix/Diag. 0.10E-03 16.1 0.32544318 -5724.9981819920 -2.41E-05</span></p>
<p class="p1"><span class="s1"> 3 P_Mix/Diag. 0.10E-03 16.1 0.32540810 -5724.9982060548 -2.41E-05</span></p>
<p class="p1"><span class="s1"> 4 P_Mix/Diag. 0.10E-03 16.1 0.32537302 -5724.9982301087 -2.41E-05</span></p>
<p class="p1"><span class="s1"> 5 P_Mix/Diag. 0.10E-03 16.1 0.32533795 -5724.9982541538 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 6 P_Mix/Diag. 0.10E-03 16.1 0.32530289 -5724.9982781901 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 7 P_Mix/Diag. 0.10E-03 16.1 0.32526782 -5724.9983022175 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 8 P_Mix/Diag. 0.10E-03 16.1 0.32523276 -5724.9983262361 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 9 P_Mix/Diag. 0.10E-03 16.1 0.32519771 -5724.9983502459 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 10 P_Mix/Diag. 0.10E-03 16.1 0.32516265 -5724.9983742469 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 11 P_Mix/Diag. 0.10E-03 16.1 0.32512760 -5724.9983982391 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 12 P_Mix/Diag. 0.10E-03 16.1 0.32509256 -5724.9984222225 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 13 P_Mix/Diag. 0.10E-03 16.1 0.32505752 -5724.9984461970 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 14 P_Mix/Diag. 0.10E-03 16.1 0.32502248 -5724.9984701628 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 15 P_Mix/Diag. 0.10E-03 16.1 0.32498745 -5724.9984941198 -2.40E-05</span></p>
<p class="p1"><span class="s1"> 16 P_Mix/Diag. 0.10E-03 16.1 0.32495242 -5724.9985180680 -2.39E-05</span></p></div><div> <br></div><div> Here it seems that is converging, but the EPS_SCF remains very high. <br></div><div>When I use intermediete values of ALPHA, like 0.1 or 0.05, the calculation goes slow, but tends still to converge to the ground state. </div><div><br></div><div>Is there something that I can use to converge my calculation to the excited state ? </div><div><br></div><div>Thanks, </div><div>Ivan</div><div><br></div><div><br></div><div><br></div><style type="text/css">
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