NAME

       cht - chemtool drawings analyzer

SYNOPSIS

       cht [options] filename.cht

DESCRIPTION

       cht  is  a  commandline  tool  to derive the sum formula and molecular mass of the molecule depicted in a
       chemtool drawing file.  It is also available from within chemtool to calculate these data for the current
       structure or a marked fragment of it.

       cht currently recognizes the element symbols  C, H, O, N, P, S, Si, B, Br, Cl, F, I, Al, As, Ba, Be,  Bi,
       Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, In, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Sb, Sc, Se, Sn, Sr, Te, Ti, Tl, V,
       Zn  (that is, all main group elements except the noble gases, and the first row of transition metals) and
       the abbreviations Ac, Ade, Bn, Bu, iBu, tBu, Bz, BOC, Cyt, CE, DBAM, DMAM, DMTr, Et, Gua,  Me,  Ms,  MOC,
       MOM, MMTr, Ph, Pr, iPr, Tf, Thy, Tol, Tr, Ts, TBDMS, TBDPS, TMS, TMTr, Ura, Z.

       It can handle two levels of parentheses; e.g. P[OCH(CH_3)_2]_3.

       When  cht  detects  any duplicate (overlapping) bonds in the drawing file, it will prepend an exclamation
       mark to the calculated (and likely wrong) sum formula.

OPTIONS

       cht understands the following options:

       -h, --help
              Displays brief help and list of options.

       -e, --exact
              Calculate exact mass for MS.

       -v, --verbose
              Be verbose.

       -d, --debug
              Be extremely verbose.

BUGS

       cht can misinterpret molecules that contain the 'aromatic ring' symbol, as it uses a fixed search  radius
       to  identify  the aromatic system that it denotes.  It also does not handle the 'partial double bond', so
       you should avoid these two in drawings that you intend to use with cht.

       A label that is offset from the corresponding bond end by more than five pixels  is  not  recognized,  so
       that the default CH2 or CH3 group enters the calculation in its place.

       In general, one should check the plausibility of the generated sum formula wherever possible.

SEE ALSO

       chemtool(1)

AUTHOR

       Radek Liboska

1.6.13                                            June 17, 2001                                           CHT(1)