From owner-nwchem-users@emsl.pnl.gov Fri Apr 8 12:34:51 2005 Received: from odyssey.emsl.pnl.gov (localhost [127.0.0.1]) by odyssey.emsl.pnl.gov (8.12.10/8.12.10) with ESMTP id j38JYpxQ028963 for ; Fri, 8 Apr 2005 12:34:51 -0700 (PDT) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.12.10/8.12.10/Submit) id j38JYpxk028962 for nwchem-users-outgoing; Fri, 8 Apr 2005 12:34:51 -0700 (PDT) Date: Fri, 08 Apr 2005 12:33:49 -0700 From: Edoardo Apra Subject: Re: B3LYP implementation In-reply-to: <4256DA5C.50107@chemistry.ohio-state.edu> To: "Jason D'Acchioli" , NWChem Users Message-id: <4256DC9D.7080306@pnl.gov> MIME-version: 1.0 Content-type: text/html; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Accept-Language: en-us, en User-Agent: Mozilla Thunderbird (X11/20050407) References: <4256DA5C.50107@chemistry.ohio-state.edu> X-OriginalArrivalTime: 08 Apr 2005 19:33:49.0470 (UTC) FILETIME=[E37083E0:01C53C71] Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk Extracted from
http://www.msg.ameslab.gov/FTP/GAMESS_Manual/refs.pdf

                          Density Functional Theory
                          ------- ---------- ------

            There are actually two DFT programs in GAMESS, one
         using the typical grid quadrature for integration of
         functionals, and one using resolution of the identity to
         avoid the need for grids.  The default program is
         METHOD=GRID is discussed below, but we will begin with a
         description of METHOD=GRIDFREE.  The final section is
         references to various functionals, and other topics of
         interest.  

         For convenience in comparing to other DFT programs, the
         following table matches DFTTYP to their input keywords:
             GAMESS   NWChem      MOLPRO2000    Gaussian94     
             Slater  slater            S           HFS
             Gill    gill96
             PBE     xpbe96
             SVWN    slater vwn_5    S,VWN         SVWN5
             SLYP    slater lyp      S,LYP         SLYP
             Becke   becke88           B           HFB
             BVWN    becke88 vwn_5   B,VWN         BVWN5

             BLYP    becke88 lyp     B,LYP         BLYP
             B3LYP   -see note-      B3LYP
          This table applies to both grid and grid-free DFTTYPs.

             Note that B3LYP in GAMESS is based in part on the VWN5
          correlation functional.  Since there are five formulae
          in the VWN paper for local correlation, other programs
          may use other formulae, and therefore generate different
          B3LYP energies.  For example, NWChem's manual says it uses
          the "VWN 1 functional with RPA parameters as opposed to the
          prescribed Monte Carlo parameters", but NWChem can be made
          to use the VWN5 formula by
              xc HFexch 0.20 slater 0.80 becke88 nonlocal 0.72 
                   lyp 0.81 vwn_5 0.19
          If you use some other program, its B3LYP energy will be
          different from GAMESS if it does not employ VWN5.

Jason D'Acchioli wrote:

B3LYP implementation
Hi Edo,

Unfortunately, I've read the section you're referring to, and
examined the table. There is no indication of how b3lyp is used, with
respect to the local correlation. The nearest I can tell is, from the
equation on the same page, it might be vwn_1_rpa. Does this mean NWChem
implements B3LYP differently from Gaussian /and/ Turbomole?

Thanks,

Jason

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