{"id":430810,"date":"2025-05-05T14:59:37","date_gmt":"2025-05-05T14:59:37","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/chemkin-error\/"},"modified":"2025-05-05T14:59:37","modified_gmt":"2025-05-05T14:59:37","slug":"chemkin-error","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/chemkin-error\/","title":{"rendered":"CHEMKIN error"},"content":{"rendered":"<p>&lt;p class=&#8221;&#8221; data-start=&#8221;227&#8243; data-end=&#8221;239&#8243;&gt;Hi everyone,&lt;\/p&gt;&lt;p class=&#8221;&#8221; data-start=&#8221;241&#8243; data-end=&#8221;329&#8243;&gt;I&#8217;m running into a couple of issues while preprocessing a CHEMKIN input file:&lt;\/p&gt;<\/p>\n<ol>&lt;li class=&#8221;&#8221; data-start=&#8221;331&#8243; data-end=&#8221;686&#8243;&gt;&lt;p class=&#8221;&#8221; style=&#8221;text-align: left;&#8221; data-start=&#8221;334&#8243; data-end=&#8221;686&#8243;&gt;&lt;strong data-start=&#8221;334&#8243; data-end=&#8221;381&#8243;&gt;Error: Problem finding Arrhenius parameters<\/strong>&lt;br data-start=&#8221;381&#8243; data-end=&#8221;384&#8243;&gt;Even though all necessary parameters are present in the input file, I&#8217;m still getting this error. Interestingly, the issue seems to occur only with longer or more complex reactions. Shorter reactions don&#8217;t trigger the error. Could the reaction string length or formatting be causing this?&lt;span style=&#8221;color: #ba372a;&#8221;&gt;<strong>Screenshot of the error:<\/strong>&lt;\/span&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/05\/05-05-2025-1746456751-mceclip0.png\" \/>&lt;span style=&#8221;color: #ba372a;&#8221;&gt;<strong>Reaction in the inpot file:<\/strong>&lt;\/span&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/05\/05-05-2025-1746456943-mceclip1.png\" \/>&lt;\/p&gt;<\/li>\n<p>&lt;li class=&#8221;&#8221; data-start=&#8221;688&#8243; data-end=&#8221;969&#8243;&gt;&lt;p class=&#8221;&#8221; data-start=&#8221;691&#8243; data-end=&#8221;969&#8243;&gt;&lt;strong data-start=&#8221;691&#8243; data-end=&#8221;760&#8243;&gt;Error: MAXORD = 12 must be increased to accommodate this reaction<\/strong>&lt;br data-start=&#8221;760&#8243; data-end=&#8221;763&#8243;&gt;It seems like the number of species involved in a single reaction exceeds the default &lt;code data-start=&#8221;852&#8243; data-end=&#8221;860&#8243;&gt;MAXORD<\/code> limit. How can I manually increase the &lt;code data-start=&#8221;900&#8243; data-end=&#8221;908&#8243;&gt;MAXORD<\/code> value to allow more reactants\/products in a single reaction?&lt;span style=&#8221;color: #ba372a;&#8221;&gt;<strong>Screenshot of the error:<\/strong>&lt;\/span&gt;&lt;\/p&gt;<\/li>\n<\/ol>\n<p>&lt;p&gt;&nbsp; &nbsp; &nbsp; <img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2025\/05\/05-05-2025-1746457015-mceclip2.png\" \/>&lt;\/p&gt;&lt;p class=&#8221;&#8221; data-start=&#8221;971&#8243; data-end=&#8221;1017&#8243;&gt;Any help or tips would be greatly appreciated!&lt;\/p&gt;&lt;p class=&#8221;&#8221; data-start=&#8221;1019&#8243; data-end=&#8221;1037&#8243;&gt;Thanks in advance!&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-430810","topic","type-topic","status-publish","hentry","topic-tag-ansys-chemkin","topic-tag-chemkin","topic-tag-chemkin-import-1","topic-tag-chemkin-mechanism","topic-tag-chemkin-mechanisms","topic-tag-chemkin-pro"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["430810"],"_bbp_subscription":["503873","14415"],"_bbp_author_ip":["163.117.64.52"],"_bbp_last_reply_id":["431094"],"_bbp_last_active_id":["431094"],"_bbp_last_active_time":["2025-05-08 14:29:24"],"_bbp_reply_count":["1"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["503873","14415"],"_btv_view_count":["199"],"_bbp_topic_status":["unanswered"]},"test":"kleskiing-uc3m-es"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/430810","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/430810\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=430810"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}