Project created and time granted. -- John Roberts Argonne National Laboratory CELS Systems [email protected] On 2/21/17, 11:15 AM, "[email protected] on behalf of [email protected]" <[email protected] on behalf of [email protected]> wrote: Hello, A new project on the LCRC cluster has been requested. Please forward the information on to the LCRC Allocation sub-committee. Applicant's name: Mark Pfeifle Applicant's institution: ANL Applicant's division: CSE Project Name: pozdyn Project title: Dissociation Dynamics of Primary Ozonides in Alkene Ozonolysis Associated funding: DAAD (German Academic Exchange Service) Other Systems: Linus (CSE) (no fixed time allocation, depending on current total load) Science: Ozonolysis is a major tropospheric degradation process for alkenes. In the first reaction step, a cyclic primary ozonide (POZ) is formed which is subsequently decomposed into a Criegee intermediate (CI) and a carbonyl compound. The CI population is initially hot due to the exothermic POZ formation. This nascent energy distribution of the CI is essential to adequately model the yields of promptly decomposing and stabilized CI. These quantities in turn are of considerable interest because the thermalized CI acts as an atmospheric oxidant for various species and enhances aerosol formation. It is commonly assumed that the excess energy is distributed statistically among the fragments in the spirit of phase-space theory. However, this assumption is questionable when the exit channel potential energy surface is strongly repulsive, as is the case with POZ decomposition. In this project, direct dynamics calculations for C2H4 + O3 are carried out. Besides con certed POZ cleavage, a step-wise diradical pathway contributes comparably to the reaction flux. Density functional theory based trajectory calculations, initiated at both exit transition states, will serve as a basis to test the statistical partitioning assumption and to provide appropriate input distributions for CI master equation calculations. Project description: The trajectory calculations will be carried out using a self-made driver program by one of our group members (http://tcg.cse.anl.gov/papr/codes/dint.html). It interfaces either the Gaussian 09 or Molpro 2012/2015 program packages to do the actual electronic structure calculations. One typical trajectory run (ca. 1000 time steps using 4 gradient evaluations per iteration) takes about two days on a single processor with density functional theory methods and a moderate-sized one-electron basis set (Gaussian 09). We expect to carry out around 200-300 trajectory runs to achieve statistically significant results. This has to be done for two different transition states that are kinetically relevant. The DFT calculations can be run in parallel in principle. However, according to initial tests, the parallelization efficiency is not optimal for these kind of jobs. Therefore, the quantum-chemical calculations themselves will be run as single-core jobs. Parallelization will be simply achieved by running N separate trajectory jobs on one node (e.g. N=16 for the blues machines). The computational burden within the driver routine is negligible compared to the cost of the electronic structure calculations themselves. In addition to the DFT runs, CASPT2 calculations using Molpro are planned for at least one of the transition states. These are computationally more expensive than DFT calculations, but otherwise the same considerations about parallization apply in this case, too. Presumably, only one member will work on this project. Industry partnership: Project URL: Requested allocation: 54000 Q1: 0 Q2: 18000 Q3: 18000 Q4: 18000 Justification: Storage requirements: The requester has used undetermined amount hours of their initial startup project. In addition to approving an initial amount, please specify a Category and Subcategory for this project. For a list of the current selection of approved categories, please see: https://wiki.lcrc.anl.gov/wiki/Processes/Categories Once the Allocation committee has approved the project, please go to the Project Management page to create it: https://accounts.lcrc.anl.gov/projects.php Thank You, The LCRC Accounts System _______________________________________________ allocations-admins mailing list [email protected] https://lists.lcrc.anl.gov/mailman/listinfo/allocations-admins