OLDCHAIN 

Description

CHAIN was developed as a tool for finding a specific transition state lying between the two provided minima. CHN (also FULLCHN and CHECKCHN) was developed later as an improved version of the original CHAIN. For a while, the original CHAIN method could still be accessed using OLDCHAIN. Now in AMPAC 8, OLDCHAIN is no longer supported and will cause the job to exit. CHN or FULLCHN should be used in place of OLDCHAIN.

The ordering of molecules differs between OLDCHAIN/CHAIN and the newer CHN/FULLCHN/CHECKCHN, so old files must be converted to run properly using the newer CHN methods. {The GUI can be used to automatically convert the molecule ordering to the new CHN style.} CHAIN can be used in place of OLDCHAIN to keep old jobs running but this is not recommended.