| 7:25:05 AM PST - Tue, Jan 11th 2011 |
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Hello,
It is impossible to change some of the dispersion correction coefficients in DFT-D method. For example the C6 atomic coefficients and radii scaling factor are fixed. When one needs to change the DFT-D method for some type of interactions it is crucial to change some of the coefficients.
I changed my version of nwchem to include c6 and radii scaling read from input file but I don't know the internal structure of nwchem good enough to do it properly. I've made only ad hoc corrections. I someone wants it I could include my files.
I noticed some things in code:
-In seems that damping function coefficient alpha is stored as dft:alpha in dft_input.F file, but xc_vdw.F tries to read dft:vdwalpha entry from database.
-Alpha is set to 20.0 (because database read fails). The default value of alpha should depend on ivdw: it was 23.0 in original Grimmes paper (so 23.0 if ivdw=1 and 20.0 otherwise).
- In xc_vdw.F line 392: c6 values are unnecessary set to be -1.
Best regards,
Karol Struty?ski
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