This chapter of the document provides a detailed description of the input and output formats for the CEA (Chemical Equilibrium with Applications) program, developed by NASA Lewis Research Center. The program is used to calculate chemical equilibrium compositions of complex mixtures and is applicable to various types of problems, including rocket performance, shocks, and detonations. The input files consist of two main types: thermodynamic data (thermo.inp) and thermal transport property data (trans.inp), which are common to all problems, and specific problem input datasets. The problem input datasets are in a free-form format and include datasets for reactants (`reac`), problem parameters (`prob`), output options (`outp`), and additional species considerations (`only`, `omit`, `inse`, `end`). The `reac` dataset specifies reactant names, relative amounts, temperatures, enthalpies, and other parameters. The `prob` dataset includes case identification, problem type, fuel-oxidant mixture values, and options for rocket, shock, and detonation problems. The `outp` dataset allows users to customize output tables, including energy units, intermediate debugging information, and specific output variables. The chapter also outlines the program's output, which includes input data, tables of results, intermediate output data, and iteration matrices. The tables of results cover thermodynamic mixture properties, thermal transport properties, rocket performance parameters, shock parameters, and Chapman-Jouguet detonation parameters. Intermediate output data provides insights into the iteration process, including the number of iterations, solution vectors, and composition corrections. Overall, the chapter serves as a comprehensive guide for users to prepare input files and understand the output format, ensuring accurate and efficient use of the CEA program for various chemical equilibrium calculations.This chapter of the document provides a detailed description of the input and output formats for the CEA (Chemical Equilibrium with Applications) program, developed by NASA Lewis Research Center. The program is used to calculate chemical equilibrium compositions of complex mixtures and is applicable to various types of problems, including rocket performance, shocks, and detonations. The input files consist of two main types: thermodynamic data (thermo.inp) and thermal transport property data (trans.inp), which are common to all problems, and specific problem input datasets. The problem input datasets are in a free-form format and include datasets for reactants (`reac`), problem parameters (`prob`), output options (`outp`), and additional species considerations (`only`, `omit`, `inse`, `end`). The `reac` dataset specifies reactant names, relative amounts, temperatures, enthalpies, and other parameters. The `prob` dataset includes case identification, problem type, fuel-oxidant mixture values, and options for rocket, shock, and detonation problems. The `outp` dataset allows users to customize output tables, including energy units, intermediate debugging information, and specific output variables. The chapter also outlines the program's output, which includes input data, tables of results, intermediate output data, and iteration matrices. The tables of results cover thermodynamic mixture properties, thermal transport properties, rocket performance parameters, shock parameters, and Chapman-Jouguet detonation parameters. Intermediate output data provides insights into the iteration process, including the number of iterations, solution vectors, and composition corrections. Overall, the chapter serves as a comprehensive guide for users to prepare input files and understand the output format, ensuring accurate and efficient use of the CEA program for various chemical equilibrium calculations.