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Dear Dr. Zou, Thank You for the further clarification! One another thing I am a little curious about -- only in CPCM+SMD calculation the escaped charge is reported (in my case, enormous 0.46984). Is that because of some threshold for things to appear in output, or due to a different algorithm in use (for IEFPCM, even with #P there is no sign of escaped charge)? Dear Dr. Klamt, That's why I was surprised by the results I had got, because I have read before, well, at least the abstract of the article You cited (due to the lack of access) and Your article of 2011 (DOI: 10.1002/wcms.56) where You argued that, although it was proven that the best value of x in the equation for COSMO is 0.5, "[u]nfortunately, several reimplementations of COSMO, including C-PCM, set the value of x to zero either by default or fixed." Can this be the reason? Or is it simply because SMD model in Gaussian is optimized for IEFPCM, not CPCM? (Maybe Dr. Zou can comment on that.) You also mention that "in the literature the COSMO approximation is often claimed to be applicable only to polar solvents, it needs to be emphasized that for neutral compounds the COSMO approximation with x = 0.5 provides very accurate results down to ε = 2". Maybe this is why COSMO is not that popular? On the other hand, if, as Dr. Zou said, the differences in computational cost arise only in really large molecules, maybe software developers just feel it is not that urgent to implement COSMO if they already have another methods implemented… By "the equation" I mean the equation of COSMO scaling factor for unscreened charge density, f (ε) = (ε – 1) / (ε + x) --------------------------------------------------------------------------- To mention some other details, the differing part in the output is the following: ***** CPCM_SMD.out No special actions if energy rises. Using charges instead of weights in PCMQM. Inv3: Mode=1 IEnd= 5838075. Iteration 1 A*A^-1 deviation from unit magnitude is 2.78D-15 for 865. Iteration 1 A*A^-1 deviation from orthogonality is 1.65D-15 for 711 187. Iteration 1 A^-1*A deviation from unit magnitude is 3.11D-15 for 813. Iteration 1 A^-1*A deviation from orthogonality is 1.65D-15 for 1142 64. Escaped charge = 0.46984 Error on total polarization charges = 0.30616 SCF Done: E(RB3LYP) = -492.141763479 A.U. after 13 cycles NFock= 13 Conv=0.34D-08 -V/T= 2.0086 SMD-CDS (non-electrostatic) energy (kcal/mol) = -1.55 ***** IEFPCM_SMD.OUT No special actions if energy rises. Inv3: Mode=1 IEnd= 5838075. Iteration 1 A*A^-1 deviation from unit magnitude is 3.55D-15 for 317. Iteration 1 A*A^-1 deviation from orthogonality is 2.67D-15 for 629 474. Iteration 1 A^-1*A deviation from unit magnitude is 3.33D-15 for 317. Iteration 1 A^-1*A deviation from orthogonality is 2.19D-15 for 545 224. Error on total polarization charges = 0.01601 SCF Done: E(RB3LYP) = -492.138961313 A.U. after 13 cycles NFock= 13 Conv=0.35D-08 -V/T= 2.0086 SMD-CDS (non-electrostatic) energy (kcal/mol) = -1.55 Yours sincerely, Igors Mihailovs ISSP UL On 08/09/17 22:59, Lufeng Zou
g09gv5_+_gmail.com wrote:
On 09/09/17 04:16, Andreas Klamt
klamt#cosmologic.de wrote:
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