Although the compound system after retrieval, edition or Data Format conversion can be stored in the form of the Compound File, the same information can be saved explicitly as the compound data file.
The differences between two files are as follows;
The compound file does not include the information of thermodynamic data, whereas the Compound Data File includes the informaion of the thermodynamic data of compounds.
Both are written in binary so that users cannot edit directly neither of files. In MALT session, the compound file can be read and reedited or modified by the Data Format conversion, but within MALT session, the Compound Data File cannot be read nor edited again.
Instead, the Compound Data File contains essentially the same thermodynamic information as those given by MALT Direct. Thus, the Compound Data File can be created inside MALT or in the MALT related software gem/CHD. In gem/CHD, the thermodynamic data can be obtained by MALT Direct and can be saved after utilization in such software.
Since the Compound Data File cannot be edited in any place, modification of the Compound Data File can be made only through the edition of the compound file which contains essentially the same data as the Targeted Compound Data File. For such a purpose, it is highly recommended to save a set of compounds into the Compound File as well as into the Compound Data File.
Care must be execized when the data stored in the user data base are included in such a procedure. When the user data text file is edited and the time stamp of the compiled user database has changed, the information stored in the Compound File is not necessarily validated and some informaion may disappear. Even in such a case, the thermodynamic data stored in the Compound Data File will not be affected in such edition/compilation of the user database. The information stored in the Compound Data File can be accessed in anytime directly from the software like gem and CHD and will provide the same results for the same calculation conditions.
Thus, utilization of the Compound Datafile provides convenient and usefull setup of the thermodynamic data set for a particular series of thermodynamic analyses. In gem/CHD, the Compound Data File is usually saved together with the calculation conditions saved as project file. This makes sure that at anytime, results and associated data will be recalled.