[CP2K-user] [CP2K:18243] Re: How to speed HF up

[Augustin Bussy]

Hi Dobromir,

you should keep in mind that HFX is inherently an expensive method (compared to GGA). From your input file, I would say you are already using all the tricks I know of:

  1.  Using the ADMM  method
  2.  Using a truncated Coulomb operator, although I have to warn you about using extreme values such as 2.0 Angstrom (~6 is usually good)
  3.  Using the largest possible value for MAX_MEMORY
  4.  Using a loose EPS_SCHWARZ threshold. Here too, 1.0E-6, may be on the limit

Also, I think that your EPS_DEFAULT value might be dangerously loose, if you want accurate results. You could optionally try to use the RI-HFX method by adding the &RI subsection in &HF. Default parameters should be good enough. There is however no guarantee that it speeds up you particular calculation.

Best,
Augustin


________________________________
From: cp2k at googlegroups.com <cp2k at googlegroups.com> on behalf of DMT <dobromirak at gmail.com>
Sent: Thursday, December 22, 2022 12:02 PM
To: cp2k <cp2k at googlegroups.com>
Subject: [CP2K:18243] Re: How to speed HF up

I tried

                !&PBE_HOLE_T_C_LR
                !    CUTOFF_RADIUS 6.0
                !    SCALE_X 0.25
                !&END PBE_HOLE_T_C_LR

in &XF_FUNCTIONAL and

            &HF
                FRACTION 0.25
                &SCREENING
                    EPS_SCHWARZ 1.0E-6            !DEFAULT 1.0E-10, TYPICAL -6 - -9, FOR STABLE HFX
                    !SCREEN_ON_INITIAL_P T         !FOR A GOOD INITIAL GUESS FROM A .WFN
                &END SCREENING
                &INTERACTION_POTENTIAL
                    POTENTIAL_TYPE TRUNCATED    !TRUNCATED 1/r (Coulomb) POTENTIAL FOR SPEED UP
                    CUTOFF_RADIUS 6.0            !SHOULD BE < HALF THE CELL
                    T_C_G_DATA /home/lsd/cp2k_data/t_c_g.dat     !DATA FOR THE EVAL OF TRUNCATED GAMMA FUNC
                &END INTERACTION_POTENTIAL

in &XC and there is no significant (if any) speed up.

I even played with the CUTOFF_RADIUS (values from 2.0 to 6.0) and nothing changes.

Am I missing something ?

Best Regards,
Dobromir

On Tuesday, December 20, 2022 at 8:31:44 PM UTC+2 DMT wrote:
Hello,

I have heard that there must be a way to speed HF (for hybrid DFT methods) up. Can you help me with that ?

Best Regards,
Dobromir

--
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com<mailto:cp2k+unsubscribe at googlegroups.com>.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/64f47d87-163a-4a6d-8061-c9b0b660b928n%40googlegroups.com<https://groups.google.com/d/msgid/cp2k/64f47d87-163a-4a6d-8061-c9b0b660b928n%40googlegroups.com?utm_medium=email&utm_source=footer>.

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/GV0P278MB0370A2BCC0DDEB6B04044436D3E89%40GV0P278MB0370.CHEP278.PROD.OUTLOOK.COM.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20221222/ed2c5dea/attachment-0001.htm>