short range + long range wPBE

Hi Zilong,

I am not sure I completely understand your entire question. I'll try to answer it as clearly as possible.

>>if I want use wPBE as DFT part and set omega=0.160 bohr-1, alpha=0.2, beta=0.7, which following definition is correct?

You could try the following:
xc xwpbe 1.0 cpbe96 1.0 hfexch 1.00
cam 0.160 cam_alpha 0.20 cam_beta 0.70

Here, the long-range aymptotic behavior of the HF term would be 0.9 * HF. If you want to use a different coefficient for the xwpbe, then you can change the 1.0 next to it to the appropriate value.


>>I do not fully understand the meaning of the number, such as in (xwpbe 0.8) or (xwpbe 0.7 xpbe96 0.1)
The 0.8, 0.7 etc above correspond to the mixing coefficient of the exchange or correlation part of the functional

Hope this helps.

Best,
-Niri
niri.govind@pnnl.gov

Hi Chandra,

The above definition is for the traditional range-separated xc functionals, where you have short-range DFT and long-range HF.

For long-range DFT and short-range HF, as in the HSE functional, you can define it as follows, where we use the srhfexch.

HSE03:
xc xpbe96 1.0 xcampbe96 -0.25 cpbe96 1.0 srhfexch 0.25
cam 0.33 cam_alpha 0.0 cam_beta 1.0

HSE06:
xc xpbe96 1.0 xcampbe96 -0.25 cpbe96 1.0 srhfexch 0.25
cam 0.11 cam_alpha 0.0 cam_beta 1.0

Hope this helps.

Let me know if there are any issues.

Best,
-Niri
niri.govind@pnnl.gov