From owner-nwchem-users@emsl.pnl.gov Wed Feb 6 09:56:35 2008 Received: from odyssey.emsl.pnl.gov (localhost [127.0.0.1]) by odyssey.emsl.pnl.gov (8.14.1/8.14.1) with ESMTP id m16HuYIe021354 for ; Wed, 6 Feb 2008 09:56:35 -0800 (PST) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.14.1/8.14.1/Submit) id m16HuY1x021353 for nwchem-users-outgoing-0915; Wed, 6 Feb 2008 09:56:34 -0800 (PST) X-Authentication-Warning: odyssey.emsl.pnl.gov: majordom set sender to owner-nwchem-users@emsl.pnl.gov using -f X-Ironport-SG: OK_Domains X-Ironport-SBRS: 3.9 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAMmDqUfRVYTxi2dsb2JhbACQMgEBAQgCAgQJChEFli2GJg X-IronPort-AV: E=Sophos;i="4.25,313,1199692800"; d="scan'208";a="43257880" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition:x-google-sender-auth; bh=TkevUSJ3cJ3e6PRGZqkQ6ogX+tuzqc9G/QIolh7tQUU=; b=WOoMZ15gL+drkzQYmZfjXZe2aUbzqLrQLPY5vYbAERGfZzhJqMopD5UhaAKWUKWPuQ+wltPi3kDR4Y7i6JKMWr13dc2PLNUGV60XvyxyZKPr2kVq3n/IEwlZPLJtDpfLa2DeWqbHxwqZ6YvbASUm4vylLvtrt6f5Ahy4/pn8i+s= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition:x-google-sender-auth; b=GJRgdrdgGBqPldwGO86Kv5Y7aH+7BiUbZtLBzc54hwvsShvhQcj3UAtHiPwinEx6lOxRqmzzjDlh7ICyJM4dI0A3ffYLKScEZfwJRrhJ0ZjINu1NgbyB55/u33fLbA4bQdlliBNgPUnL7ySZzLiB87VF/WRODkkYFAii4Ch3X2g= Message-ID: Date: Wed, 6 Feb 2008 18:56:31 +0100 From: "Alvaro Vazquez" To: "users nwchem" Subject: [NWCHEM] imaginary freq using auxiliary functions-DGauss A2 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Google-Sender-Auth: aa0bf6e03de276d5 Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk Dear nwchem-users, I'm studing small clusters of double negative charged oxoanions and n-water molecules . To reduce the time-machine during the optimizations I'm using auxiliary functions, only in 4 center coulombic integrals. Within the optimized geometry I do a numerical frequencies analysis. In all the structures where is interacting water-water I found imaginary freqs. (method B3LYP/TZVP/A2) Performing the similar procedure now without auxiliary functions I reach a similar structure, with an analitical hessian, and all the freqs are real. (method B3LYP/TZVP) The imag. freqs. are around -150.0 cm**-1. Have you any idea to avoid this small values? Is a problem with the accuracy of numerial procedure to get the hessian matrix? In the last part of this mail is an example. Thanks in advance. Alvaro -------------------------------------------------------- INTPUT -------------------------------------------------------- Title "3a010203" Start 3a010203 echo memory total 900 Mb scratch_dir /usr/tmp geometry geo units angstrom symmetry c1 C 0.67946277 0.29199286 -0.27051293 O 1.63791780 1.15462781 -0.34090810 O -0.52284364 0.69294286 0.11022418 O 0.87616261 -0.95337773 -0.57438632 H -1.34804825 -2.43834759 0.58918709 O -0.51780464 -2.93260279 0.49642985 H 0.06952074 -2.19392602 0.11041790 H 1.03359324 2.68061431 0.07014288 O 0.37160056 3.39079455 0.35343548 H -0.36130362 2.74685930 0.42280969 H -1.67591106 -0.20128192 -0.16422310 O -2.48758448 -0.83695091 -0.41127146 H -2.06615402 -1.39615085 -1.07596865 end driver maxiter 200 tight end charge -2 basis "ao basis" C library "TZVP (DFT Orbital)" O library "TZVP (DFT Orbital)" H library "TZVP (DFT Orbital)" end basis "cd basis" H library "DGauss A2 DFT Coulomb Fitting" O library "DGauss A2 DFT Coulomb Fitting" C library "DGauss A2 DFT Coulomb Fitting" end set geometry geo dft mult 1 xc b3lyp direct iterations 200 end task dft optimize freq end task dft freq -------------------------------------------------- OUTPUT ---------------------------------------------------------------------------- Normal Eigenvalue || Projected Derivative Dipole Moments (debye/angs) Mode [cm**-1] || [d/dqX] [d/dqY] [d/dqZ] ------ ---------- || ------------------ ------------------ ----------------- 1 -164.046 || 0.040 0.142 -0.300 2 -20.537 || -0.093 -0.059 -0.036 3 0.000 || -0.763 0.156 0.018 4 0.000 || -0.147 -0.256 -0.136 5 0.000 || -0.012 0.062 -0.658 6 0.000 || -0.058 0.566 -0.421 7 0.000 || -0.408 -0.429 -0.149 8 0.000 || 0.203 -0.361 -0.434 9 83.426 || -0.105 0.048 0.002 10 112.166 || -0.318 -0.114 -0.238 11 128.053 || 0.058 -0.400 0.511 12 150.219 || 0.034 -0.234 -0.256