Index error.  Fixes issue #25
Index error.  Fixes issue #25

wesbarnett/pymbar,jchodera/pymbar,Lnaden/pymbar,jchodera/pymbar,jchodera/pymbar,kyleabeauchamp/pymbar,wesbarnett/pymbar,mrshirts/pymbar,kyleabeauchamp/pymbar,mrshirts/pymbar,kyleabeauchamp/pymbar,mrshirts/pymbar,choderalab/pymbar,wesbarnett/pymbar,kyleabeauchamp/pymbar,jchodera/pymbar,choderalab/pymbar,wesbarnett/pymbar,Lnaden/pymbar,Lnaden/pymbar,choderalab/pymbar,mrshirts/pymbar