Instruction about versions of PACEs:

Currently, there are three versions of PACEs (vers1.3-1.5), each of them improved
based on the previous one. These versions of PACEs are detailed as follows:

Ver1.3,
the version reported in J Chem Theory Comput, 2012, 8, 4413 and used in folding
of peptides and small proteins;

Ver1.4,
improved based on ver 1.3 for modeling side-chain packing in proteins and used in
simulations of small globular proteins as well as folding landscapes of Trp-cage 
and WW-domain. This version was reported in J Phys Chem B, 2013, 117, 42, 13367.

Ver1.5,
Basically identical to ver 1.4 except for improved parameters (i-->i+4 HB strength)
for stability of long helices and used in simulations of trans-membrane proteins as
reported in J Chem Info Model, 2014, 64, 1003 
This force field can still be used to fold beta-hairpin (gb1p D47P mutant) correctly despite
the enhanced helical propensity of peptides (unpublished data).

The instruction presented in the user guide is in general applied to system setup with
all versions of PACEs. Here is some exception. Given that if you want to use version 1.4,
please go to FF/ver14/ to check out all files needed for version 1.4. Also, in the last step
of the system preparation, a code called "genPairPACEXX" from programs/genpair/ is needed.
The code can be generated by doing the following:

make genPairPACEXX

Please make sure that "XX" in "genPairPACEXX" corresponds to the correct version of PACE you 
are using.