This runtime error occured with a very large protein-lipid-water system:

At line 1552 of file mmfp.f (unit = 6, file = 'stdout')
Fortran runtime error: Expected INTEGER for item 19 in formatted transfer, got REAL
(1X,5I4,12F8.3)
^


What I found when I looked at the code was that in source/misc/mmfp.src, SUBROUTINE STGEO(many arguments) contained the statements
IF(PRNLEV.GT.5)THEN
WRITE(OUTU,100) NTGEO, NGEO(NTGEO), I, IGEO2, JGEO2,
$ XREF, YREF, ZREF, TREF,
$ XDIR, YDIR, ZDIR, DROFF, DTOFF,
$ FORC, P1, P2, P3
100 FORMAT(1X,5I4,12F8.3)

The WRITE statement lists 13 real variables, but the FORMAT statement only made room for 12. On my copy of mmfp.src, I changed that FORMAT statement to:
100 FORMAT(1X,5I4,13F8.3)
_________________________
John Penniston