| 6:01:00 AM PST - Wed, Feb 27th 2019 |
|
It seems there is no obvious problem to identify the dftb2 optimized one is a minimum for some practical use, e.g., reorganization energy calculation for some molecules, and the first excited state parameters of TDDFT TPA calculation of thiol using a certain functional tried by me .
I used MP2 and a large basis set to optimize it and RHF for frequency analysis, but still got the warning.
The MP2 semi-numerical HESSIAN calculations using the large basis set eliminate the warning of the geometry from MP2 with the same basis set but still get it for that from DFTB2.
Please note the thermochemical composite G3MP2 in GAMESS using the MP2 and DFTB2 optimized initial geometries, respectively, all gave gaseous heats of formation of -47.82 kJ/mol-1 at 298.15K, in good agreement with that of -46.15kJ/mol-1 in NIST Chemistry Webbook.
|
|
|