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I found the nice userd example with the standard functional in the latest MRCC manual but I wonder if one can also use ssr (local-scaling approximation) for the userd functional.

For example, as shown in example 18 on page 74, doing XYG9[f2]@B44LYP but substituting the LDA correlation part into ssrLDA_C_VWN with omega=0.5 at the second userd block.

Thank you for the help!

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  • $\begingroup$ I got a message from a developer and they said it can be done by adding a long-range Hartree-Fock exchange with a small global parameter like this >> 0.000000001 lrHFx 0.5 where 0.5 stands for the omega value. They said this lrHFx should be put in both first and second userd block. And then, at the second block, one can use the ssr functional like 0.21 ssrLDA_C_VWN where 0.21 is just an arbitrary global parameter and that ssr functional will use the 0.5 as a range-separated parameter. $\endgroup$
    – nesquik91
    Jun 8, 2022 at 17:38
  • $\begingroup$ Did you get this working in the end? $\endgroup$ Dec 1, 2022 at 16:06
  • $\begingroup$ I've emailed nesquik91 to write a self-answer if possible. $\endgroup$ Feb 6, 2023 at 21:26

1 Answer 1

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Here is an example input file (MINP) for calculating $E_{XC}=1.0E^{HF}_X+1.0E^{srLYP}_C$ where the range separated omega value equals to 0.33.

basis = 6-31g
symm  = off
dft   = userd
2
1.0 HFx
0.000000001 lrHFx 0.33
2
1.0 ssrGGA_C_LYP
0.000000001 lrHFx 0.33


mult     = 1
mem      = 5000MB

unit=angs
geom=xyz
3

O   0.0000   0.0000   0.0626
H  -0.7920   0.0000  -0.4973
H   0.7920   0.0000  -0.4973
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