Tutorial Molfiles and SDfiles

CTfilcs originated in the time of punched cards and therefore their format is quite restrictive. For example, blanks usually arc significant and several consecutive spaces cannot simply be replaced by a single one. Spaces may correspond to missing entries, empty character positions within entries, spaces between entries, or 2cros in the case of numerical entries. Thus, eveiy piece of data has a precise and fixed location within a line in a data file. Moreover, the line length of CTfilcs is restricted to 80 characters. 

The default filename extension for Molfilcs is ,mol , and for SDfiles .sdf or .sd are used. 

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