无法configure怎么办呀！

chgtg

系统是9.2，错误提示如下：
chg@linux:/data1/software/xdrawchem/xdrawchem-1.8.5> bash ./configure
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking for pkg-config... /usr/bin/pkg-config
checking for openbabel >= 1.100.2... Package openbabel was not found in the pkg-config search path.
Perhaps you should add the directory containing `openbabel.pc'
to the PKG_CONFIG_PATH environment variable
No package 'openbabel' found

configure: error: Library requirements (openbabel >= 1.100.2) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your lbraries are in a nonstandard prefix so pkg-config can find them.

这是什么错误呀，怎么解决呢？
谢谢！！