Hi Ghemical community, I'm trying to make ghemical v1.91 to work on my Linux Fedora 4. I've managed to install the libghemical 1.91 (with MOPAC7, MPQC and OpenBabel add-on) after quite a bit of a struggle and an advice from the posting on this forum about changed order of parameters in keyval.h function PrefixKeyVal, however, the issue popped up again later in ghemical installation. At least I think its the same kind of a problem. Since I can't edit the libghemical.so and am relatively new to the linux development business, I was wondering if anybody can help me out where and what to fix in order to remove the error that pops up: Here's the last echo before "make" shuts down: make[1]: [/usr/gamess/ghemical-1.91/bin/ghemical] Error 1 (ignored) g++ -o /usr/gamess/ghemical-1.91/bin/ghemical main.o project.o views.o fileio.o filetrans.o mtools.o objects.o camera.o spline.o ribbon.o plane.o surface.o gtk_dialog.o glade_dialog.o gtk_project.o gtk_views.o gtk_project_view.o gtk_graphics_view.o gtk_plot_views.o /usr/gamess/ghemical-1.91/src/glade/libdialogs.a -lm -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lgdk_pixbuf-2.0 -lm -lpangoxft-1.0 -lpangox-1.0 -lpango-1.0 -lgobject-2.0 -lgmodule-2.0 -ldl -lglib-2.0 -Wl,--export-dynamic -L/usr/local/lib -L/usr/X11R6/lib -lgtkglext-x11-1.0 -lgdkglext-x11-1.0 -lGLU -lGL -lXmu -lXt -lSM -lICE -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lgdk_pixbuf-2.0 -lm -lpangoxft-1.0 -lpangox-1.0 -lpango-1.0 -lgobject-2.0 -lgmodule-2.0 -ldl -lglib-2.0 -lglade-2.0 -lgtk-x11-2.0 -lxml2 -lpthread -lz -lgdk-x11-2.0 -latk-1.0 -lgdk_pixbuf-2.0 -lm -lpangoxft-1.0 -lpangox-1.0 -lpango-1.0 -lgobject-2.0 -lgmodule-2.0 -ldl -lglib-2.0 -L/usr/local/lib -L/usr/local/mpqc/2.3.0/lib -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.3 -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.3/../../.. -lghemical -lSCmbpt -lSCpsi -lSCdft -lSCscf -lSCwfn -lSCsolvent -lSCintv3 -lSCbasis -lSCoint3 -lSCmolecule -lSCoptions -lSCisosurf -lSCrender -lSCoptimize -lSCsymmetry -lSCscmat -lSCgroup -lSCmisc -lSCstate -lSCkeyval -lSCclass -lSCcontainer -lSCref -lfl -ldl -lpthread -llapack -lblas -lfrtbegin -lg2c -lm -lgcc_s -lmopac7 -lopenbabel -lglut -lXmu -lg2c -lm /usr/local/lib/libghemical.so: undefined reference to `sc::PrefixKeyVal::PrefixKeyVal(char const*, sc::Ref<sc::KeyVal> const&)' collect2: ld returned 1 exit status make[1]: *** [/usr/gamess/ghemical-1.91/bin/ghemical] Error 1 make[1]: Leaving directory `/usr/gamess/ghemical-1.91/src' make: *** [all] Error 1 Thank you for the response Andrej