Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3122
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
The potential energy surface for the reaction of HOCO radicals with hydrogen atoms has been explored using the CCSD(T)/aug-cc-pVQZ ab initio method. Results show that the reaction occurs via a formic acid (HOC(O)H) intermediate, and produces two types of products: H(2)O+CO and H(2)+CO(2). Reaction enthalpies (0 K) are obtained as -102.0 kcalmol for the H(2)+CO(2) products, and -92.7 kcalmol for H(2)O+CO. Along the reaction pathways, there exists a nearly late transition state for each product channel. However, the transition states locate noticeably below the reactant asymptote. Direct ab initio dynamics calculations are also carried out for studying the kinetics of the H+HOCO reaction. At room temperature, the rate coefficient is predicted to be 1.07x10(-10)cm(3) molec(-1) s(-1) with a negligible activation energy E(a)=0.06 kcalmol, and the branching ratios are estimated to be 0.87 for H(2)+CO(2), and 0.13 for H(2)O+CO. In contrast, the product branching ratios have a strong T dependence. The branching ratio for H(2)O+CO could increase to 0.72 at T=1000 K.
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Source |
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http://dx.doi.org/10.1063/1.2946696 | DOI Listing |
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