grimmedisp

This option defines how to apply Grimme dispersion correction version 3, i.e. DFT-D3.

When there is no grimmedisp in the input file, no DFT-D3 will be applied.

type

Value	bj Becke-Johnson DFT-D3 form
	zero Zero-damp DFT-D3 form
Default	None

Define form of DFT-D3. There is no default value and you must assign bj or zero.

In most cases, bj is better, but for some functionals, like M06, M062X, and M06HF, only zero is available.

three_body

Add three body corrections in DFT-D3. This is useful for large systems.

tz

If triple zeta basis sets are used, this keyword may bring some improvement.