From owner-chemistry@ccl.net Thu Jul 17 16:51:01 2008 From: "Aleksey Kuznetsov AlexKuznetsov2007() yandex.ru" To: CCL Subject: CCL: TM5.10: problems with constrained geometry optimization during a search for a transition state Message-Id: <-37361-080717164009-9803-dK6ZOgXrKFYtM/HQwwWu6Q a server.ccl.net> X-Original-From: Aleksey Kuznetsov Content-Transfer-Encoding: 7bit Content-Type: text/plain Date: Fri, 18 Jul 2008 00:06:11 +0400 MIME-Version: 1.0 Sent to CCL by: Aleksey Kuznetsov [AlexKuznetsov2007,,yandex.ru] Dear CCL Users, I am looking for a transition state for the reaction of H2 with a N2(transition metal cluster) adsorbed at MgO(100) surface, using the embedded cluster approach (MgO cluster is embedded into the point charge array) with Turbomole 5.10. In my calculation, the Mg's and O's atoms are fixed, and only H2, N2, and transition metal cluster are allowed to relax (one distance N-H is also fixed). Below there is a part of my 'coord' file: $coord 2.39032877604133 8.25913300313270 -7.32768851332685 h 3.33127069298153 9.83887033461485 -5.58504005522075 h -0.17492593800043 5.52925592375161 -7.10524544210555 n -0.04705169228237 8.16658554084386 -8.08372916213718 n 0.02396047105540 2.36709809807531 -3.74432586066866 zr -2.76503557449325 6.07384486515057 -1.92546840309758 pd 1.97586710418695 6.90664433702049 -4.17446765970979 zr 4.75623866501232 2.85042595434685 -2.04843366515992 pd -1.64927570145236 0.65155657107799 6.53597754772781 mg f -1.04006469510789 3.40790675809863 3.73058912774775 o f -3.94370461903670 -1.40503558837978 4.01708230923380 o f -3.33449361269223 1.35131459864087 1.21169388925374 mg f -6.23813353662104 -3.46162774783755 1.49818707073978 mg f -5.62892253027656 -0.70527756081690 -1.30720134924028 o f 1.54497952983392 -1.35138399890064 5.26170474285745 o f 2.15419053617839 1.40496618812000 2.45631632287739 mg f -0.74944938775042 -3.40797615835841 2.74280950436344 mg f -0.14023838140595 -0.65162597133776 -0.06257891561662 o f -3.04387830533476 -5.46456831781618 0.22391426586942 o f -2.43466729899029 -2.70821813079553 -2.58147415411064 mg f 4.73923476112019 -3.35432456887927 3.98743193798709 mg f 5.34844576746467 -0.59797438185863 1.18204351800703 o f 2.44480584353585 -5.41091672833704 1.46853669949308 o f 3.05401684988033 -2.65456654131639 -1.33685172048699 mg f 0.15037692595151 -7.46750888779481 -1.05035853900094 mg f 0.75958793229598 -4.71115870077416 -3.85574695898100 o f 6.24827192949393 -4.65750701618949 -2.61112446485111 o f 5.63906092314945 -7.41385720321014 0.19426395512895 mg f -6.52874869230583 3.35425507351396 2.48596663361786 o f -7.13795969865030 0.59790488649332 5.29135505359792 mg f -4.72909610762837 -4.76481019260023 -5.10036927300007 o f 4.44861934481647 3.46155824992470 4.97521144176682 o f -5.33830711397284 -7.52116037962087 -2.29498085302001 mg f 3.83940833847200 0.70520806290406 7.78059986174688 mg f 9.44252716078020 -6.66044758616812 -3.88539726972147 mg f 3.95384301190959 -6.71409917564726 -5.13001970334513 mg f -1.53484087634209 -6.76775076257886 -6.37464207787043 mg f -7.02352502521271 -6.82140235205799 -7.61926451149408 mg f -9.72300392359210 5.35719564349259 3.76023943848822 mg f -8.82317760989017 1.29766291405620 -0.03292860487615 mg f -7.92335133891464 -2.76186962262160 -3.82609646812971 mg f -4.23431977472149 5.41084723297173 5.00486187211187 mg f 1.25436411353019 5.46449881990333 6.24948424663718 mg f 6.74304826240081 5.51815040938247 7.49410668026083 mg f 7.64287457610274 1.45861767994607 3.70093863689646 mg f 8.54270084707827 -2.60091485673172 -0.09222922635710 mg f 1.83559486611852 -8.16726678447804 4.27392498626501 mg f -4.55291559645403 -4.16138564452078 6.82247059600573 mg f -3.65308928275210 -8.22091837395717 3.02930255264136 mg f 0.93576855241658 -4.10773405504164 8.06709302962939 mg f $intdef # definitions of internal coordinates 1 f 1.0000000000000 stre 1 4 val= 2.55362 $user-defined bonds $redundant number_of_atoms 50 degrees_of_freedom 144 internal_coordinates 323 frozen_coordinates 1 # definitions of redundant internals . . . I use RI-B3LYP method with TZVP basis set (and ECP's for Zr's and Pd's). For constained geometry optimization, I am using the command "jobex -ri -c 500 -statpt". However, I am quite confused by the output results. First of all, at the some step of optimization, the energy of the system becomes lower than the sum of energies of H2 molecules and original N2Zr2Pd2/MgO system, and the gradient of the system becomes huge: energy change : actual value = -16.27 threshold = 0.1000E-05 geom. gradient : actual value = 358.9 threshold = 0.1000E-02 Could anybody please explain why such strange huge values could appear, and which which part of the output should be used for reference? Should I look at this part of the 'job.last' file: ****************************************************************** CONVERGENCE INFORMATION Converged? Value Criterion Energy change no 16.2682530 0.0000010 RMS of displacement no 0.0250000 0.0005000 RMS of gradient no 42.3591183 0.0005000 MAX displacement no 0.1769108 0.0010000 MAX gradient no 358.9048907 0.0010000 ****************************************************************** Is there any other way how to do search for a transition state in such cases - for on-surface reactions? Thank you very much in advance. With best regards, Aleksey Kuznetsov. ------------------------------------------- Dr. Aleksey Kuznetsov Cherry L. Emerson Center for Scientific Computation Emory University 1515 Dickey Drive Atlanta, GA 30322 USA Phone: (404)727-2381 Email: akuznets[A]euch4e.chem.emory.edu -------------------------------------------