Upgrade to DFT-D4 in QChem 6.4

Hi, all,

Would it be possible to clarify what specifically was improved about the D4 dispersion in the recent version upgrade?

Can energies from QChem 6.3’s implementation be used interchangeably with those in 6.4?

I use a version that is implemented as a module on HPC infrastructure, and was recently swapped to 6.4 while I wasn’t looking. I can’t unilaterally downgrade to keep everything the same.

Thanks!