From owner-nwchem-users@emsl.pnl.gov Sat Dec 18 06:56:38 2004 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 iBIEucPg011661 for ; Sat, 18 Dec 2004 06:56:38 -0800 (PST) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.12.10/8.12.10/Submit) id iBIEuc3x011660 for nwchem-users-outgoing; Sat, 18 Dec 2004 06:56:38 -0800 (PST) Date: Sat, 18 Dec 2004 16:58:14 +0200 From: Roman Zhurakivsky Subject: value declared as constant changes To: nwchem-users@emsl.pnl.gov Reply-to: Roman Zhurakivsky Message-id: <568433964.20041218165814@univ.kiev.ua> Organization: ICC MIME-version: 1.0 X-Mailer: The Bat! (v2.10.01) CD5BF9353B3B7091 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Priority: 3 (Normal) X-Spam-Status: No, hits=-0.2 required=5.0 tests=AWL,BAYES_01 autolearn=no version=2.63 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on mail.univ.kiev.ua Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk Hello , all I have problem when optimizing molecule geometry at MP2 theory with NWChem 4.6. I started with geometry just optimized with MP2 , rotated molecule group around the ordinary valence bond and fixed value of one of the torsion angles beetween atoms of this molecular group and atoms of another molecular part with "CONSTANTS" directive of GEOMETRY block of NWChem input script. But in output log I found that this torsion value declared as constant changed by 30 degrees back to initial value of optimized molecule geometry with all free parameters. Have I done something wrong? Why value declared as constant changes? Thanks in advance > ============================== echo of input deck ============================== > title "thymine analysis" > > start sa21_th_6-311_030 > echo > print low > > geometry units an > zmatrix > C > C 1 1.463 > C 2 1.496 1 118.069 > H 3 1.093 2 110.466 1 T1 > H 4 1.779 3 35.535 2 -121.984 > H 5 1.779 4 59.272 3 -37.259 > H 6 5.387 5 58.300 4 83.418 > N 7 1.010 6 26.370 5 -172.900 > C 8 1.385 7 115.136 6 -168.114 > N 9 1.385 8 112.314 7 -179.954 > C 10 2.685 9 64.736 8 0.046 > O 11 3.561 10 39.877 9 179.958 > O 12 4.583 11 49.883 10 -0.036 > H 13 4.381 12 60.233 11 -0.004 > H 14 4.781 13 31.318 12 0.018 > constants > T1 -89.056 > end > symmetry c1 > end > > scf > direct > end > > driver > maxiter 150 > end > > basis "ao basis" cartesian print segment > * library "6-311++G**" > end > > task mp2 optimize > ================================================================================ Part of the output log of NWChem where is shown that value T1 declared as constant changed : > Final and change from initial internal coordinates > -------------------------------------------------- > Z-matrix (user) > -------- > Units are Angstrom for bonds and degrees for angles > > Type Name I J K L M Value Change > ----------- -------- ----- ----- ----- ----- ----- ---------- ---------- .... > 6 Torsion T1 4 3 2 1 -58.24401 30.81199 .... -- Best regards, Roman Zhurakivsky mailto:zhr@univ.kiev.ua