<div dir="ltr">Dear Molpro users.<div><br></div><div>I'm comparing DFT energies between Molpro and two other softwares: Molcas and Gaussian09.</div><div><br></div><div>I use:</div><div>1. two Hamiltonians: nonrelativistic and DKH2</div>
<div>2. HF method, DFT method with LDA (VWN5) and B3LYP (with VWN3) functionals</div><div>3. two types of basis sets: ANO contracted basis sets and uncontracted basis - Dunning for lighter and Dyall for heavier elements</div>
<div>4. restricted calculations for closed-shell and unrestricted for open-shell test systems</div><div><br></div><div>In order to compare the correct things, i take care of the following:</div><div>1. i check basis sets are really the same (i use spherical harmonics)</div>
<div>2. i set the same thresholds for integral screening</div><div>3. i set the same thresholds for SCF convergence</div><div>4. if DKH2 Hamiltonian is used, all calculations are done with point nucleus model</div><div>5. if DFT calculations are done, i set the grid of the analogous quality</div>
<div>6. all calculations for open-shell systems are done with unrestricted HF/DFT</div><div>7. all calculations are run without symmetry</div><div><br></div><div>As a result, i can reach a very good agreement between scf energies from all software for closed-shell systems. For example for Ne atom with ANO basis set i get:</div>
<div><br></div><div><div> RHF (nonrel) SVWN5 (nonrel) B3LYP (nonrel)</div><div> -----------------------------------------------------------------------------------------------------------</div>
<div> g09 -128.523833639 -128.208032842 -128.958538025</div><div> molpro -128.52383364 -128.20803284 -128.95853804</div><div> molcas -128.5238336388 -128.2080328424 -128.9585380272</div>
<div><br></div><div> RHF (DKH2) SVWN5 (DKH2) B3LYP (DKH2)</div><div> -----------------------------------------------------------------------------------------------------------</div><div>
g09 -128.683953423 -128.367112213 -129.118503285</div><div> molpro -128.68395342 -128.36711221 -129.11850330</div><div> molcas -128.6839534241 -128.3671122136 -129.1185032879</div>
</div><div><br></div><div><br></div><div><br></div><div>When i do calculations for open-shell systems i have very good agreement for HF method, but when i do DFT, Molpro always gives noticeably higher energy than Molcas/Gaussian09.<br>
</div><div><br></div><div>It is not a question of converging to different states. I looked at O atom and O2 molecule. </div><div><br></div><div>For example for O2 molecule with ANO contracted basis set, HF energies agree very well up to 1d-09, but for DFT agrrement is only at 1d-6 (i take care of tight convergence criteria and dense grids, so that it should not be due to numerical noise). these are the results:</div>
<div><br></div><div><br></div><div><div> UHF (nonrel) UVWN5 (nonrel) UB3LYP (nonrel)</div><div> -------------------------------------------------------------------------------------------------------</div>
<div> g09 -149.676204517 -149.32122<font color="#ff0000">44</font>39 -150.38381<font color="#ff0000">69</font>61</div><div> molpro -149.676204516 -149.32122<font color="#cc0000">35</font>135 -150.38381<font color="#ff0000">51</font>30439</div>
<div> molcas -149.676204517 -149.32122<font color="#ff0000">44</font>405 -150.38381<font color="#ff0000">70</font>099</div><div><br></div><div> UHF (DKH2) UVWN5 (DKH2) UB3LYP (DKH2)</div>
<div> -------------------------------------------------------------------------------------------------------</div><div> g09 -149.793906497 -149.43775<font color="#ff0000">89</font>47 -150.50138<font color="#ff0000">92</font>28</div>
<div> molpro -149.793906497 -149.43775<font color="#ff0000">80</font>12997 -150.50138<font color="#ff0000">73</font>85591</div><div> molcas -149.793906499 -149.43775<font color="#ff0000">89</font>499 -150.50138<font color="#ff0000">92</font>789</div>
</div><div><br></div><div><br></div><div>Conclusions for uncontracted basis set are analogous, so that it is not due to contraction scheme. </div><div>For molecules with heavier open-shell elements, the discrepancy between Molpro DFT and DFT from other software is even bigger (but there there is additional question of converging to the same ground states).</div>
<div><br></div><div><br></div><div>Do you know what can be the source of these differencies? The implementation of functionals should be the same (at least as far as i can trace it on software's websites), but maybe there is some specificity related to unrestricted DFT implementation?</div>
<div><br></div><div>Below i paste my Molpro input for O2, i can send you corresponding inputs for Gaussian09 and Molcas if helpful,</div><div><br></div><div>best regards,</div><div>gosia olejniczak</div><div><br></div><div>
<br>
</div><div>--------------------------------------------------------------------------</div><div><div> memory, 1000,m;</div><div> file,1, O2.int, new;</div><div> file,2, O2.wfu, new;</div><div><br></div><div>gthresh,energy=1.d-9,twoint=1.d-18,grid=1.d-9</div>
<div>gprint,basis;</div><div>gprint,orbitals;</div>
<div><br></div><div>symmetry nosym</div><div><br></div><div>include, O.tzp</div><div><br></div><div>geometry={</div><div>O 0.0 0.0 0.0;</div><div>O 0.0 0.0 1.2;</div><div>}</div><div><br></div><div>{uhf,accu=9.0;</div>
<div>WF,16,1,2}</div><div>{pop; individual;}</div><div>{pop; density,type=spin}</div><div><br></div><div>{UKS, LDA, accu=9.0;</div><div>WF,16,1,2}</div><div>{pop; individual;}</div><div>{pop; density,type=spin}</div><div>
<br></div><div>{UKS, B3LYP3, accu=9.0;</div><div>WF,16,1,2}</div><div>{pop; individual;}</div><div>{pop; density,type=spin}</div><div><br></div><div>INT,DKROLL=1</div><div><br></div><div>{uhf, accu=9.0;</div><div>WF,16,1,2}</div>
<div>{pop; individual;}</div><div>{pop; density,type=spin}</div><div><br></div><div>{UKS, LDA, accu=9.0;</div><div>WF,16,1,2}</div><div>{pop; individual;}</div><div>{pop; density,type=spin}</div><div><br></div><div>{UKS, B3LYP3, accu=9.0;</div>
<div>WF,16,1,2}</div><div>{pop; individual;}</div><div>{pop; density,type=spin}</div></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div>