Should ICHAIN must set to use VTSTTOOLS?

[ColinDCG]

Dear Professor,
Could you please answer me the question that should the tag ICHAIN must be set before using your vtsttools? Since when I didn't use tag IOPT, I can still grep the ICHAIN tag in the OUTCAR file. I have read your web page saying that you have a different neb scheme from the primary VASP version, I alse find your code file neb.F, so I guess it is neccessary to set the tag of ICHAIN, but I alse suspect that it would be run by defaunt since I can find the string ICHAIN in the OUTCAR file. So is it neccessary to set ICHAIN to use your tools?
Thank you!

[graeme]

The ICHAIN tag sets the type of calculation that will be run with the VTSTtools. ICHAIN=0, for example, will specify an NEB calculation which can include the climbing image. For optimizers, you can either use the built-in vasp optimizers (with IBRION) or our vtst optimizers (with IOPT).

[ColinDCG]

Thank you for your valuable advice.